ok first to the controller, there are two types of controllers, cg and matrix. you need a switched power supply. (one that turns on/off with the controller) look at some of king mikes install diagrams. (the ones pined to the top of the 360 controller page) those will show the best spot for each of the controllers. the CG spot is at the bottom center near the battery terminal, it is the mic's supply point. for matrix, there are three open ternimals at the left bottom, below the left stick. use the one far left.
now that you know the points... the cg supplies a max of 3V with new batteries, and the matrix is 2v. use these figures for the resistance calculator.
as far as the LED's..there are thousands of them, with thousands of different forward voltage requirements. so you need to check the packaging and enter this into the calculator. or post it, and I will do the math for you.
if you are using a matrix controller, and need the 3v..use the battery supply adn add an on/off switch somewhere. or burn it and buy a CG LOL