Poor Poor Laptop

I think I'm killing my laptop.

It's an early 2008 MBP. Right before the unibody. It's a solid laptop. Only been two years since I got it, so it should be in it's prime, right?

No. I'm bad. I treat my laptops like people treat their PCs. Within a month of having it, the laptop was partitioned and I installed Steam and played my way through Portal and half of HL2. I later installed some software for my cell phone along with Spore. Beyond that, I left the Windows XP side alone. On the OSX portion, I have 4 different browsers, Steam, Sims 3, 3 different IM clients, Microsoft Office, roughly 10gb of music (I know, it's small, send me more music plz), and too many images and word files to count. For Christmas, I simply asked for a new battery because the old one wasn't holding a charge too well. I use my laptop a lot.

About every month I have to do a SMC reset and I'm sure that's not doing any good either. My guess is I'm generating too much heat by playing games. I'm thinking I need to do a fresh install of the operating system and delete the Windows partition (since Steam is on Mac now). But, you know, to do that I'd need to transfer my files to another computer for safe keeping. So I'm either going to have some fun with the unused computer in the basement or buy myself an external hard drive and go to town. The latter is the more sure method, but the former seems like a good challenge.

So, I dunno. This is kind of an uncharted area for me. I fix small things for my computer inept mother. Like plugging in wires that came loose or making sure whatever program is up to date. I sat and watched as my laptop was partitioned and data from my old laptop was transferred to this one. But I've done some research. I grasp the general concept. I think I can accomplish my goal by myself, but any advice from the more technically inclined would be appreciated. It's only a half step away from life support as it is.