Windows XP by default, if you install the East Asian languages through the languages sub-menu in Control Panel, will allow you to type Chinese (and just about most other langauges) in programs. Just make sure you have the East Asian languages installed, enabled under the Keyboard section (also in Windows Control Panel), and that the language toolbar is enabled after completing all these steps (PM or IM me if you need further assistance).

However, if you are truly interested in learning Chinese, I HIGHLY HIGHLY HIGHLY recommend you spent a LOT of time writing out the characters, because learning to write Chinese is about 50% of the challenge of learning the language itself. You think learning to speak and read is hard -- learning to write properly and efficiently (so that your writing actually looks somewhat native) is a whole different level. Doing things on the computer is not going to do you good. Just my $.02.