Heaven, the first night it took 10 (!!) attempts to get him to stay asleep when I put him down. Rocked him to sleep (fully) first, then put him down. Patted and ssshhhhed him then picked him up again when he started crying. Then started again...
The first night's the worst - it can take a LOOOOONG time, so try and prepare yourself mentally first. Once you've done it though, it should get easier. By the fourth night DS went down first go.
Good luck