I'm having trouble with my administrator information
Boot off the recovery partition, open up terminal, and type

reset password

That should bring up a dialog that will allow you to change your password If, for some reason, the default account is not set as admin, you will need to boot into Single User Mode (⌘-S when starting up) and type:

mount -uw /
rm /var/db/.AppleSetupDone

This makes the file system writeable, and then removes the file that tells OS X that you've setup the system. Hit Ctrl-D to continue your boot and you should get the "Welcome to Macintosh" startup and you will be able to setup a NEW account (make sure it is a new account). This account will be an admin account.