This is one thing I heartily recommend from HD. They have some excelent bike cleaning and finish care kits. Some include buckets, sponges and lint free rags.
I don't like to use a hose on a bike unless I have to, and then I keep the flow to a trickle to make sure water doesn't go where it shouldn't.
As for cleaning the engine, as long as it is cold, and you make sure to wipe it down completely before starting it, you don't have to do anything special beyond making sure nothing gets into the electrics or intake system.
