There is a whole lot of things you can do to adjust the rudders, it's just how much you want to check (alignment, breakaway tension, rake, cams). If you simply want to check the alignment, as said before make sure that the rudder assemblies are on correctly (the arm should be pointing towards the centre of the boat on both sides). Lock the rudders down and check the alignment of the rudders with a tape. You should aim for the front edge of the rudders being 1/8 to 1/4 of an inch closer together than the back edge. If they are not, you should find a screw or some other mechanism on the tiller bar that lets you change the alignment. It's fairly simple and shouldn't take very long.
If you want to adjust the rudders further then check out further details in the sailing and tuning guide at
http://www.hobiecat.com/support/pdfs/sailguide.pdf