This guide will help you to organize and run your school auction. The information in this guide can also help you to raise funds for your favorite charity or non-profit.
Although I never expected to be an eBay Powerseller, here I am giving advice to others. I would just like to give something back to the community as it is a very nice place to be. The advice distilled in this guide will be culled from years of research and experience as a fulltime eBay seller. I have experience with school auctions and work for a PBS Television station in my spare time. (yes, lots of fundraising!) I hope that this information proves useful to you, as we all know that schools need all the funds they can get due to the lack of priority in the governmental funding sector for education, regardless of the rhetoric appropriated by the current administration. In my particular community; private schools (which account for 45% of my Urban West Coast city's grade K-12 school population)  as well as my children's public schools have turned to auctions as a popular way to raise money for gaps in their budgets. Schools may have five or six major fundraising events per year, and eBay can be a part of that effort. The information in this guide can be used by any non profit or club. I will be referring to schools in this guide for the purpose of simplification, but feel free to use the information for any fundraising project.
In the US, individual donors account for just over 75% of all monies raised for a virtual panoply of charities, causes and non-profits. eBay offers a very powerful tool that enables the potential for these organizations to sell to individuals world-wide, not just in their local community. In addition, it is a very inexpensive risk-free option to increase your fundraising profits and revenue by selling unused and unwanted items from your school community to bidders that want those items. Even the school itself may have unwanted items that are actual collectables to others (library discards); and if you have time to sort and list them, even the lost and found at school may even turn up some sellable items.
You will want to follow your schools regulations about lost items. For example at my youngest child's school lost & found items are donated at a designated time at the end of the school year, but families are given ample time and a deadline to make sure that they have claimed all of their lost items before this happens.
Your virtual store can be an ongoing project, run concurrently with a live auction event, and/or be a one time or annual event. Once you get started, it will be easy to see how eBay can raise much more of your needed funds than wrapping paper or magazine sale fundraisers. You don't even have to change your current popular fundraisers. Most schools find that an eBay auction can be a perfect way to disperse the items that did not sell in their live and silent auction events. It can also be a lot of fun for the school community to bid on items that their school is selling, such as school logo merchandise. 
It is also a great intro to auctions for families that may not be aware of the money they could be saving by shopping for themselves on eBay. If people save money on items for their house and family on eBay for example,  they will personally have more to use for needed private tutoring, sports or lessons that are so important yet expensive for most families and usually not included at school. The perfect way to get more people involved in the eBay auction project that you start for your organization is to make it fun! Have meetings that are informative, but also engaging, empowering and entertaining. Many schools also have computers that can be used for such a project in classrooms or the library. You could have a auction listing party with a group of people to make the work go quicker and utilize the pooled knowledge of your group.
Please check with the appropriate members of your organization in regards to the proper accounting procedures and legalities of what you plan to auction so that you have a plan in place and the proper permission to act in the interest of your organization to sell items on eBay. Giving works also allows individuals to donate part or all of the proceeds of their own auctions to your group if you are registered as a non profit through a valid third-party verification service. You can see the details of this special service at:  Giving Works

Choose your format: DIY (do it yourself) or Professional service:
The first thing to consider is whether you want to run your own school auction. If you have a school newsletter or website, you could advertise for a person in your community who is already a eBay seller to run your auctions. Or you could utilize a service like Missionfish to certify you as a non profit and allow you to display the giving works logo in your auction. There are some other benefits such as the guarantee offered by Missionfish that may prove helpful. There are pros and cons to using Missionfish which are best explored by viewing their website. Get the information at either of these links: Giving Works    Missionfish

DIY essentials include a professional digital camera with good quality image capabilities and a internet based bank account to accept payment. You will potentially be selling to people worldwide, and you need to be able to accept foreign currency without the huge fee a bank would charge to do so. This will also let you accept credit card payments for items. Of course there is a fee charged for this service, but you'll find for record keeping and the convenience that it offers your customers is worth it. You may also decide to accept money orders through the mail because not everyone likes using credit cards or feels comfortable with on-line payments.  The largest such bank is the PayPal service owned by eBay. There are some other internet bank options if you search the web.   PayPal

There are also professional trading assistants available to help you with your school auction. There are drop-off storefront operations as well as individuals whose talents you can utilize. They will charge a fee, but a lot of the larger services will charge a lower commission for non profit fund-raising auctions. The fee may be worth it if you don't have any volunteers available to run your auctions. The drawback is the value restriction or minimum they may have in place on what they can sell for you. 
Take a look at some of the larger one's sites such as Bidadoo, isoldit, and Auctiondrop for example, as there is much information you can glean from their experience about what sells. You will want to screen the items you list for sale based on others experience in order to save valuable time.  Trading Assistants

What to sell and where to get it:
Your school community has a vast array of items that can be "found" and sold for a profit. Don't overlook prosaic items such as cars and special parts for them, business equipment and electronic parts. For ideas, browse these sections on eBay:
sporting goods 
eBay Motors  electronics

Some of the items most families have lying around unused and unwanted include outgrown sports equipment and clothing, as well as books and musical instruments that are sought after and very sellable. Items that are easy to ship will be the best option. You don't want to spend extra time and money packaging bulky items. You may want to offer local pickup for such items as furniture, breakable items, or other heavy things. Please see the shipping options section of this guide for details on mailing items. Shipping Options

 You will need to gather these items at a central location to photograph and have the listings written. Access to the items is very important to be able to write accurate descriptions of what you have to sell. Measurements of items is very important, as well as a detailed description. You will need to make sure that the brand names in the auction headings are spelled accurately because eBay is essentially a collectors and brand-driven merchandise venue. The search function is very important for buyers to find your items and you need to have key words in your title that will attract bidders to your listing. Brand names such as Gap and Old Navy clothing will not be easy to sell on eBay and will not yield much profit. You can only use the actual brand name of the item being sold in your listings and no others. If you violate the eBay listing rules your auction can be removed.
Luxury goods and collectables as well as expensive/trendy brands will be the easiest to sell. Go to the advanced search function on ebay to research your items for their potential, and also as a guide to pricing your items. You just need to check the box that will search for auctions that ended in the past 30 days to see which items have sold and at what price. You might be surprised at what you will discover about your items. Advanced Search
Additionally I must advise that brand names such as the Gap and Old Navy clothing will not be easy to sell on eBay and will not yield much profit. You are probably better off only selling items that are in very good or brand new condition. If there are any flaws or issues with your items, be sure to note that very clearly to avoid problems later on. You will need to have firm guidelines in place for payment and a return policy if you are allowing returns. If you need tips on how to authenticate,sell, collect payment for and/or ship your items you can use the following eBay resources:
Authentication PayPal payment  Seller Education  sell internationally  shipping center

Research, Research, Research
Given that eBay has extensive search features, the process of gathering information to help you with your auctions is easy. You can start with all sorts of selling guides that exist for new eBay sellers, or you can study similar groups and their auction formats and methods. Missionfish is one huge data base of certified non profit organizations that you can search for by location and type. There are mission statements describing the goals of each member organization, as well as links to auctions they are currently running.
I know that the release of this guide is near the end of the school year for most children. But this may be all the better for planning purposes for next year. I also want to add that the information and ideas can be used for funding your child's homeschooling and summer activities. Thank you, and good luck!