Here's one more vote for CarbonCopyCloner.
It is SUPERIOR to Time Machine -- no ifs, ands, or buts.
CCC will create a BOOTABLE backup that will prove itself the first time you have "a moment of extreme need" -- say, you turn on the computer and it won't start, try again to no avail, etc.
With a bootable backup, you'll be alive again in a couple of minutes, and able to work on your problem drive. With a TM "backup" your options will be severely limited.
TM creates the illusion of "easy backup", and it actually is just that -- very easy to backup, just flick the switch in System Prefs and you're all set, right? The problem is when things go wrong, and the user tries to access the TM backup, and..... can't.
CCC is the better way to go. It requires just a bit more thought and effort at the beginning of the backup process -- but delivers its rewards "at the other end", when you really NEED them.