MacBook Died.... How do I access files from my Harddrive??

I have a macbook pro core 2 duo 2.4 ghz 17" that just failed due to the graphics card. I can get it fixed at the apple store because of it is a know issue but I'd like to backup all the files on the hard drive just in case something happens when they are fixing it. I failed to ever use "time machine" (stupid of me I know, I know) If I remove my harddrive from my macbook and put it into an external harddrive case can I just copy/paste all of the system files onto my external harddrive? Would that be able to be used as a restore point later on if I ever needed it? Also could I access word documents, jpegs, mp3s and edit any of these types of files or delete them from that original hard drive or would that mess it up when I put the harddrive back into the computer and try to start up. I have heard that this would be ok as long as I dont edit or delete any of the system files. I just don't want to edit or move something even if its not critical to the system if its going to keep it from booting up when I replace the harddrive. Thanks for the help!!