The 'Control Crying' method works. I went to a sleep school with my then 15 month old daughter to learn this method.
You put them to bed awake when they are showing tired signs, and tell him "It's time to go to sleep". Then you leave the room. Let him cry for 2 minutes, then return, put him back in bed, tell him the same thing again, and walk out. This time let him go for 4 minutes, before you return.
Do exactly the same thing every time, increasing your absence by 2 minutes - 2,4,6,8 & 10. Once you have let him cry for 10mins, if he's still going, go back in, do the same thing and let him go for another 10, then another 10. If he is still going after that, start at 2 minutes again and repeat.
If at any stage while you are timing his cries, he stops for 30 seconds or more, restart the clock. So if you are timing 4mins and at 2mins he stops for a while, when he starts crying again, start timing the 4 minutes from then.
Within a day, my daughter would be asleep before I got to 6 minutes and after a week, I was lucky if I had to go in at all. Now she's 2 and goes to bed as soon as I put her down. The key is to be consistent. Do the exact same thing every time and they quickly realise that its bed time and you are not going to give in. It also teaches them to put themselves to sleep without any assistance.