Backing up data

[Gamekid]

I've had a very minor problem happen to my ps3. The part that controls the disc sliding in has broken. I have already contacted Sony and they have sent me both an email and a box. It would be a good idea to back up data. To back up data from a ps3, does it matter what kind of media you use? I have an external hard drive that I can use. Once I back up data on my hard drive, then I would use the restore system command to transfer the data back onto the hard drive? How do I verify that my data has been backed up successfully? If I view my hard drives contents on my computer, what does the back up file look like?

I did some reading in the online instruction manual, one other question, if you back up your data, restore the ps3 system and then restore your data, then your account user name and password are shown when you sign in or do you have to enter it in again before signing in?