Unless you have less than 512 Megs of RAM, normal Ubuntu will work fine and is the easiest way to get into Linux, I think. The Ubuntuforums are excellent, getting help is really easy and there's a wonderful selection of various how-to's for common stuff. I sugggest you get the normal Ubuntu version (next one will be out end of month, Hardy is current) to get full GUI, not server version, and then lookup how-to's on the forums for whatever you want to do with it.

Ubuntu is really, really good and easy to use and setup. In addition to my own machines, I've put it on my parents computer (web and email use, they love it, comparable machine to yours) and my wife's laptop. Everybody's been happy with its ease of use and speed. Can't recommend it enough. Remember the forums - they might be Ubuntu's best feature and the one thing that really sets it apart from other distros.