Hi A.,
I HIGHLY recommend reading "Healthy Sleep Habits, Happy Child" by Dr. Marc Weissbluth for understanding biological sleep rhythms and how/when they mature/evolve. You did not say what your son's daily sleep schedule is, whether he is napping and when and what his bedtime is at night. How long has he been in a regular bed and why did you move him from his crib? Our pediatrician (and many other sources) told us that children that young don't understand imaginary boundaries like a regular bed and it is best to keep them in their cribs, using a crib tent if they climb out. What I would do is put him back in his crib. At this age my daughter's sleep schedule was this: wake up at 6-7am, morning nap at 9am, afternoon nap at 1pm and bedtime at 6-6:30pm. I found that my daughter couldn't easily go to sleep if the bedtime was later. While Dr. Weissbluth states that the FASTEST way to correct bad sleep habits is to let them cry it out he does give other methods. I used a modified cry it out. Make sure you have a calm and quiet bedtime routine and at the end put him to bed and leave. If he cries, wait 5-10 mins before responding, then calm him down without picking him up or talking. Repeat this process, waiting longer each time until he falls asleep. This method can take a few weeks with a stubborn child, but consistency is the key. This method doesn't work with all children though. I have ended up letting Paige cry it out as she got older and it usually takes a few days. If you want to email me I can give you my personal experiences and what I tried.
Sincerely,
L.