Huge difference between a single screw and twin inboards. First off, you wont need your rudder around the docks, just make sure they are amidship (centered). try and remember a shopping cart, if you push on the cart handle from the left side the cart will go to starboard, push the right side and the cart goes to port, same on a boat, left throttle forward and bow goes to starboard, right throttle forward and the bow will go to port. To make a 360 degree turn, put one engine in forward and one in reverse, the boat should spin on its pivot point. Backing in is similar, you need to get a feel for it, practice in open water and you will see how she reacts to diffrent positions. While backing go slow, in and out of gear, correct any direction by adding forward gear shift to the dirrection you want the bow to go. Left for startboard and right for port. You will get the hang of it, just go slow! The easiest way to back in is to stop across the dock, then spin the boat left or right usubg one forward engine and one in reverse, stop when you are in line to back in and put both in reverse, remember slow, and bump them out of gear when you make way ini reverse. Bump them forward to stop the boat. Hope this helps, good luck! Let us know how you make out.