I can only comment on what we did, but DS wouldn't sleep either and I just found it easiest to put him on the spare bed and lie with him for a while until he drifted off or got really calm and sleepy. Then i'd put him in his cot.

I did eventually stop doing this though (or i would have had no life - and no-one else would be able to settle him!). Maybe after about 2 weeks.

He's pretty good now.