if you're relatively inexperienced with computers and comfortable with windows, stick with that (aka don't get an apple).
Dell is pretty good, lets you customize, and usually has fair prices. Some people complain about them, but you have various people who will complain about all of them. It's the companies used the mosts that have the highest # of complaints, but they all break down equally (except apple, which breaks down 1% more often).
check out dell's website, they usually offer ideas on what you should get with your computer, depending on what you need. at the very least, it would be a good start.