Definitely do-able. Get a good book (useful for the rest of your cycling life) such as Zinn & The Art of Road Bike Maintenance and it shouldn't be too hard to do everything you need to do.

If you have questions, google it or search on here (chances are they've been asked before). And if you can't find the answer, ask us. Sometimes we can be helpful.

Bikes are complicated, but only because they're made up of a whole lot of very simple mechanisms and sizes.