When considering buying a used or even a new laptop, the first thing you need to do is to determine your computing needs.
* word processing
* browsing web pages
* moving the laptop from home to work (weight)
* gaming
* on-line shopping
* a database application
* personal finance
* is battery power important
Check out the Minimum Systems Requirements needed to do all of the your applications. They will not come with the laptop, as refurbished laptops often only include the Operating System (OS). If they don't include an installed OS, then be prepared to install it yourself. This is not for those that don't know what they are doing, so research what is involved before buying one without an OS.
Once you understand what you really need, you need to determine your budget.
Most old laptops do not have working batteries. If you need a battery, shop around to figure out how much they cost. You should know that on older laptops, batteries don't last more than an hour or two, so purchasing a new battery for the purpose of longer battery life may not be worth the expense. And by all means, stick with a name brand… IBM, Dell, Toshiba, Compaq-HP.
If you are new to computers and you want to browse the World Wide Web, you will need to obtain the services of an ISP (Internet Service Provider). There are basically two types of Internet access options: broadband (cable modem, DSL, satellite) and lowband (dial-up). Broadband is the preferred type since download speeds can range from 128kbs to 6000kbs. The faster the better, of course. But, if your budget is tight, dial-up works just fine for typical browsing and e-mail usage.
Your choice of ISP's will be dependent upon two things: budget and location. If the budget allows and you don't mind paying upwards of $35-50+ per month, you can purchase a broadband connection. However, even if money were no object, your physical location will determine what types of services are available to you. Broadband is not available everywhere (with the exception of satellite). If you have a telephone line, you can always choose dial-up. AOL's bread and butter is dial-up users. Do your research to determine what is available in your area and compare costs.
And for you gamers out there, you definitely need a reliable broadband connection. Gaming over a lowband connection can be a frustrating experience and sometimes even impossible. You will need to check out the minimum systems requirement for the games you are interested in using to make sure the CPU speed and the RAM and graphic chip requirements will support the games you wish to play.
Once you have figured out your budget and your needs and the requirements of your laptop it is time to search for the laptop of your desires.
Some people choose to search at www.ebay.com. If you do be sure to check out the seller to be sure you will have a smooth transaction.
Many people don't want the hassle of bidding, so use your favorite search engine: Google or Yahoo or MSN for the terms "used laptops" or "refurbished laptop".
An important thing to keep in mind is how will the vendor treat you should there be a problem. If you don't like their attitude or they don't pick up the phone shop elsewhere. Price is important, but if you have a problem and spent the least amount of money possible the vendor may not have any resources available to help you after you have purchased and spent your money.
If all the above seems like too much of a hassle, then buy a new computer. It will cost around $700 + but will come with a new battery and a one year warranty, although some new ones seem to have only 90 day warranties. It will also have the latest Windows XP system and an 800 number to call the vendor, should their be a problem. I'd call the 800# first before buying to get an idea what kind of support they will provide.