Basically, you use approach and retreat, starting in a small area--stall--to introduce the halter. Then leave it on for short periods. Then, halter, unhalter, halter, unhalter, etc., until it's no big deal.
The first address is more of a commercial. If you get RFD.tv, start watching. The program to sell the videos should be repeating soon.
RE: tying with a halter and lead, if you have a fence post where you can run a long (15') lead rope or use a lungeline, you can duplicate the tie ring. You run it through, "scare" (throw your arms up) and get the 2yo to run backwards, then soothe, pull back to a couple of feet, and do it many times, and you will desensitize him to being panicked while tied. You let the rope run all of the way through if he pulls it that far, and the horse resists less and less. LOTS AND LOTS of PRAISE really helps. One week of this every day should train your colt to stand tied quietly. The sessions should be 15-30 minutes long. Very long training sessions don't accomplish much in a young horse.