Regarding carpet.....If you want a professional looking job, you should hire professional carpet installers. Look at and call some of the carpet buying groups like Abbey Carpet, Carpet One, etc. The estimates should be free. Empire's prices are pretty inflated.
Caveat Emptor here.
The main reason is that it takes professional tools like a power stretcher to install carpet properly. Yes, you can rent them, but rental tools are not in the best of shape, and unless you can get your installation done in one day, it'll get expensive.
Installing hardwood floors is a little easier. Take your time, read the directions, measure twice/cut once, and make sure the base molding and quarter-round molding looks great. Nothing is worse than a brand new wood floor made to look crappy by shoddy trim work.
Good luck!
Streamer1212