You want a laptop so you're browsing eBay for a bargain.  That's cool.  There are thousands of laptops to choose from here on eBay.  If you're new to the computing world, or eBay in general, educate yourself on a few things before you start.  First let me say that if the listing shows a stock photo, beware!  Many sellers use a stock photo and what you'll get is much older and worn than in the photo.  So, look for actual photos in the listings.  Check the seller's feedback.  How many negatives they have received?   Look for words such as "Sold As-Is".  Another thing to be careful about is shipping charges.  When you see a laptop, with nothing more than the laptop, you should assume that the shipping charges should be under $25.00 to just about anywhere in the USA from anywhere in the USA.  When you see "Flat Rate Shiiping" and then a shipping charge of $35.00-$50.00, that should be a red flag.  Having sold laptops myself, I have shipped across country for under $20.00 with insurance over $700.00.  

Having said all that, some things about the laptop you'll want to consider before you bid.  First, consider the brand and model number.  On many laptops, you can get a lot of information if you Google the brand and model.  You can sometimes find reveiws about that particular model.  Just like cars and appliances, some models rate better than others.  My personal preference is DELL, Toshiba and Alienware.  Again, you need to know which model you are considering.  If you're bidding on a used laptop, you can often get a printable owners manual via the internet at no charge.

The motherboard is the heart of a computer.  The motherboard will determine how much (if any) upgrading can be done.  Hand in hand with the motherboard is the processor.  The type, brand and speed of the processor will determine how fast or slow your computer is capable of running. many of todays software titles can usually be run on a slower machine but you'll find yourself annoyed at the hourglass.  Look for a minimum of 1.4 Mhz when looking at the information in the listing.  If you're a gamer, look for 1.8 to 2.0 or faster.  Otherwise, you'll be disappointed in the performance. Video cards are important if your needs are graphically demanding.  Look for a good brand name and model when looking at a listing.  Do a Google search to find out more about the graphics card capabilities.  RAM is very very important when buying a laptop.  For Vista, you'll want to max out the RAM (random access memory)  The amount of the memory your computer can accept and utilize is dependant on the motherboard.  If the laptop has two slots that will accept 1 Gig each, you can run Vista without problems.  Buy the most memory you can afford and that your laptop will accept.  RAM modules are not very expensive and worth what you pay in performance.  Wifi capabilities are standard now a days.  The computer may have an internal WiFi card or it can be one that pops in and out of the slot.  My preference is internal, but either works fine.  With the internal card, you still have the slot available in the event you want to add a card from your wireless cell phone company.  USB ports are a way to connect other periphicals such as camera, printer, PDA, etc.  When looking for a laptop, find out how mnay USB ports it has.  My preference is at least 4.  USB ports can also be added very easily with a card that pops in and out.  Bluetooth is always a plus.  Bluetooth allows you to connect to other devices via radio waves.  It's good to have an internal bluetooth module even if you are ready to use it now.  You will soon enough.  Send your document to a printer in another room wirelessly via bluetooth, use a bluetooth mouse without the need to use a USB to connect.  The laptop screen needs to be bright with no scratches or dead pixels.  Of course the screen brightness can be adjusted for times when you're on battery power and you want to conserve power.   many sellers don't guarantee the laptop battery.  If the listing says they don't guarantee battery, assume it is dead and that it will need to be replaced.  A laptop with a dead battery can only be used where you can plug it in.  Hard drive size should be no less than 40 MB and most people will find 60-80 more than enough.  If you are going to install large programs or save large files such as music or photographs on the hard drive, consider getting at least 60MB.

I would highly reccommend a good laptop cooling pad.  Fast processors build up a lot of heat and  if not dissipated can ruin the hard drive and processor.  Cooling pads cost from $20.00 up, so they are well worth what you'll pay for that insurance. 

Finally, I would recommend thoroughly checking out the laptop after you receive it.  If the seller offers a warranty of seven days, make sure you have gone through all the computer functions before their return policy runs out.  Once again, I'd like to say, check the sellers feedback.  Check how many happy and unhappy buyers they've had.  Check their comments too.  If they respond rudely to buyers, stay away.  You don't want to be the next unhappy buyer.