L.R.
Hi C.,
A great book to read for info on age appropriate sleep needs is Healthy Sleep Habits, Happy Child by Dr. Marc Weissbluth. I think he is amazing and has TONS of experience to back up his info. My daughter went to one naps at about 15 months old and the transition was rough. She isn't the average child when it comes to sleep though. Dr. Weissbluth's book give you averages and percentages for sleep needs, plus the cues to look for. When we transitioned to a single nap we moved her bedtime earlier to compensate and it worked well. Email me if you want more info on Dr. Weissbluth.
Sincerely,
L.