External Hard Drive Advice Needed

[Snowflake]

I am not in a position to afford a new PC right now, but I am rapidly running out of hard drive space. This was the one thing I cheaped out on when I bought my PC, it's 20Gb with about 2Gb left. I have a Dell 8200 with a Pentium 4 with a 1.4 Ghz processor. I know I do not have 2.0 high speed USB ports, just regular 2.0 ports as far as I know.

I do not have the smarts to install, so I am looking for an external hard drive for the PC. Do any of those in the know about the inside of PCs have a recommendation for an external hard drive I can pick up at Staples (closest place to my house).

I'm looking online and see several to choose from, but here are two that look like they might fit the bill:

Maxtor 200Gb

Maxtor 200Gb One Touch

There are several other brands, but Maxtor is a name I recognize, not that this means anything. Any suggestions, advice?

Secondly, once I take the plunge and hook it up, I know I can drag and drop folders to it. How would I redirect a program like iTunes to store everything on the 2nd drive? I'm an idiot about this, I admit it.

Thanks in advance, LoT is the font of all good knowledge!
Donna