Re: Bigger RAM
You need to purchase some more RAM cards. You can get different sizes (and types, like DDR1 or DDR2, etc) like a 512mb card or a 1gig card. Though, I don't think your computer would need much more RAM, 1gig is a good standard at the moment. If you wanted more RAM, it's usually for video editing or extreme gaming, and I don't think the other parts of your computer would keep up with those sort of things.
Feel free to ask more questions.