So I have been recently contemplating taking out a small bank loan to clear my overdraft (which isn't very big at all) and pay for a few upcoming things. One of the reasons as well would be to build up a good credit history - I currently don't have one at all and I have been told it is vital if/when I want to apply for a mortgage.

Firstly - Is this the right way to build up a good credit rating?
Secondly - ARP for any back is pretty high. Is this normal?
Thirdly - Should I just wait for my Christmas Bonus and keep clear of anything like this?

Grown-up help.