I've done a few disk upgrades on MacBooks and it can be a bit worrying taking apart the machine!
To save time its worth having a look at 'SuperDuper!'. This utility allows you to make a full bootable backup of the hard drive. Particularly useful if you've got a spare SATA caddy as it saves reloading the machine from fresh and also allows you to keep all your utilities/files/photos/etc as is.