A good general use video for you would be a VisionTek Radeon HD 2600PRO for $42.99. It's not the greatest at gaming. but it offers much improved graphics over your current on-board video and it wont break the bank.
For a little better gaming capability, a ZOTAC GeForce 8600GT 256MB for $65.99 will work nicely with your system
Alright. Thanks. So, if I buy one of these, it'll be easy enough for me to do it by myself without sending it to a computer place and spending even more money?