It's time to pick features. If you were buying a drill you'd have to decide on RPM's, ergonomic grip, weight, one or two handles, variable speed or single. This is what you need to do now. The first thing you are usually confronted with is processor speed. It basically means how many commands the chip can process in one second.
Higher numbers are better.
The fastest processors avilable now are rated at about 500MHz. You don't needed the fastest computer available, you need something appropriate for your use. A 300MHz computer is adequate for most home needs and will keep you happy for a few years to come. If you're strapped for cash, 200MHz will do fine, but you may find it lacking in power in a year or two. If you have the money to burn or really expect to edit video, buy the big boy.