S.S.
One of the best books I've read out there on the subject is called, "The No-Cry Sleep Solution". It's written by Elizabeth Pantley and it has a lot of great ideas. There may be one specifically for toddlers. I also find that giving my children a lot (or at least a little more) one-on-one attention during the day, as well as making sure they're physically tired, really seems to help. Good luck!