Lost in Tech Mumbo Jumbo

I have been treating my computer with kid gloves, and there is no doubt that my tower is on it's last legs....but replacing my computer has put me in quite a quandary. I really love my XP....Am I really going to hate Vista, like so many people have told me? Should I just switch over from desktop to laptop, so that I am portable when I need to be......although I just adore my desktop.

I don't understand a lot of the strange technical language such as what is a KVM switch and do I want one? How many rams and bytes do I need, and can I easily keep all my storage for pictures, files, documents, music, and games?

The problem is the last time I got a new computer over three years ago it was custom built for me....but this time I am frugal, savvy, and want to know more about what is going into it so that I can save money, and not spend it on things and parts I don't need. For example, my monitor, keyboard, mouse, and printer are all great, technically all I need is a new tower....but computers don't seem to be sold by the towers only. Is there a website I should be looking at that will help me solve my tech needs...help a blogger out here!