Agreed with ICOT.
You don’t need to be a Ferrari if you’re only planning on doing 20mph.
The only thing is sometimes people (usually older) don’t like that netbooks have small keyboards. Some have issues adjusting to them, so whatever you choose, do yourself a favor and make a stop at a retailer so you can check out the feel of the machine. Don’t spend a few hundred dollars only to find that you don’t like the feel.
I certainly do recommend tigerdirect for purchasing, they’re quite good, but don’t buy anything without physically seeing and feeling it first.
As far as maintaining goes, excellent suggestions above! MBAM and CCleaner should be on every PC. They’re both free for personal use. Regarding defragging… fragmentation happens over time, especially if you find yourself moving, transferring or deleting very large files. It’s not something you need to do often. Windows 7 can do it automatically for you and you don’t have to worry about it.
Anyways, good luck with your purchase!