Most important thing one should always ask oneself is what do I need the laptop/computer for. This can be for simply going online , where a decent modem for dial-up or ethernet card for LAN connections to an ASDL box for broadband, the latter being the norm or WI-FI capabilities for surfing on thr move. If you are a student make sure you look out for a decent office suite package, they are many available ,even Tesco are offering one , but Microsoft office is always a safe bet as it's widely used and you can save and move your work from your machine to your school, college or university without worrying about program compatibility issues and saving you the hassle of converting your documents from one format to another. For users who require a laptop/computer for work, this will normally be dictated by your company, computer administrator and group policy ( this is the rules set out by the company on what services the computer can access etc)But lets face it , your company should provide you with one anyway. For Gamers the most important things are a fast processor, good spec graphics card ( = or > 64mb) and spacious hardrive. finally for music lovers and budding DJ's you need a nery large hardrive capacity, high spec sound card, AV out, serial ports and line-in ports.
I hope this helps you make a educated choice on what spec laptop/computer suits you. Enjoy the Ebay experience and watch for fraudsters, the can only get you if you let them.