Check out the refurbs on Apple's site, too. Deals to be had. Recommend 512M minimum RAM. My 12" iBook has 256M and, while usable, is sluggish.

.mac is worth it. My wife has an account. She puts up webpages with pictures and captions, shares files, backs up important files to her iDrive, and uses her mac.com email exclusively. If she can do that, anyone can :)