MacBook Pro : Looking For Preupgrade Checklist?

OK, I have never really done any computer surgery before. I want to make sure I don't leave anything out before I dive in.

I have a 15" Macbook Pro Core Duo 2.4ghz 4,1 with 200 Gb harddrive and 2gb Ram. It's full, and slow when I run Fusion. I also use a ReadyNas Network storage drive, and have another external which I periodically use for Time Machine backups. The ReadyNas hold musics and video but is not a true back up. I also use Fusion with some Windows stuff. I have the Snow Leopard discs but never installed them. I also have the original install discs (1 and 2) that came with computer.

I want to do 3 things:

1) upgrde HD to 500 GB

2) upgrade RAM to max which I understand is 4gb

3) install Snow Leopard

Checklist:

1) my backup will be from Time Machine. I will do a fresh backup before starting.

2) Order 2x2gb RAM from Crucial website according to their hardware finder. Can I do more? I want the max, I do some video stuff. I think 4 is the max right?

3) Order 500 GB 7200 RPM drive from somewhere. Maybe DIY package from OCW. Don't know if one drive is better than the other.

4) Order Ifixit manuals and watch some YouTube videos to do hardware upgrade.

5) Dissassemble computer...Reassemble. Pray

6) Boot with my original startup discs....how do I do this? Never done it before. Do I put discs in computer before it is on and turn it on? Do I turn it on and then insert the discs?

7) Now I should again have Leopard on my computer with new stuff right? Need to get my things on here, will run a Time Machine Backup through System Prefs.

8) I should now have my stuff, my 3rd party apps, my music, etc. on the computer. Now I will run the Snow Leopard disc to upgrade the OS. I assume you just put these in and they go right?

I very much do not want a 2K paperweight. Would MUCH appreciate any critique to my gameplan! I don't think this process has any effect on my network storage, but any insight here would be great as well.