Like a lot of people I really love ebaying! It saves time going to the city to get your fave brand, stops you wasting gasoline to get to the destination and most of all things on here are often cheaper than outside. 

eBay coupons and cashback blogs  http://infowebbie.net/coupons  gives you sites which give you cash rebates via paypal and coupons  for all your ebay purchases, but you need to remember to click on their ebay link in order to be credited each time! The other way to maximise your chances of getting coupons is to open new ebay accounts without using them! Occasionally ebay will offer you a paypal voucher to entice you to buy.

With regards to bidding and selling smart.......

1.I've added a cool site to http://infowebbie.net/coupons that enables you to save money by finding mispelled items on eBay. Thus you can pretty much take advantage of sellers mispellings and typos, and it's free

2. I've also added another site to the same blog for auction sniping so you can bid on your items in the last few minutes/ seconds when you are away.....

You have to be careful though when too many people start bidding early on an item as they can end up higher in price than buying it brand new at your local shop. Its often good to check the prices online using google search or any other search engine.

Getting too hung up on winning something can also being very addictive...almost like gambling. Sometimes its better to let it go if the prices get a bit high because chances are someone else will list something similar later on, at a less expensive price.

Checking out alternative spellings of what you are looking for, and looking most closely at gallery descriptions without the pics can also get you great bargains. People often list things incorrectly so keep a lookout.

Don't be afraid to put up an offer when the listing allows you to do so. As a general rule, don't make an offer that is too low. Put yourself in the sellers shoes and think how much you would be willing to sell the item for without making a terrible loss (well most of these auctions and buy it nows are already heavily discounted). Most really low offers just get discarded buy the seller. Likewise of course you wouldn't make an offer that's too high.

If you want to buy and resell things, make sure it's a good brand as often you are unlikely to be able to sell well if it is an unknown one. But most importantly don't buy it too expensive because it is unlikely you will be able to sell it higher than what you paid for yourself. Secondly don't forget Ebay often has auction insertion fee-free days or insertions for just 20 cents on certain days!! Just check your email box and sell on those days as much as you can.......

Just so you don't waste your money, never be afraid to ask questions, especially when it comes to measurements. So many people end up buying things that don't fit just because a sz small in one brand is so much different than sz small in another. Eg the xs sizes in famous designer Banana, Old Navy, and Ann Taylor clothing, tend to run larger than A Byer, Wet seal and Forever 21. Also check for warranties on digital items and other specific details. Have the sellers tested the item before selling?

Apart from that make use of your paypal code coupons .....you can search for more if you search for "paypal code coupons" forums in google or other search engines (I don't think you will find any in the ebay forums as I have looked). I have also noted quite a few  companies that gives you rebates for each purchase which has been noted to be really handy in the forums. I've joined up and the amount you earn does add up.