My 14 week old son is on the following nap routine:
Wake: 6:30
1st nap: 8:00-9:30
2nd nap: 11:00-12:30
3rd nap: 2:00-3:30
Catnap: 5:00-5:45
Bedtime: 8:00 pm
Mind you, this is the ideal. The fact is that he sleeps for about 45 minutes, then starts fussing. I go in and sometimes succeed in getting him back to sleep for the rest of the nap time and sometimes not. Sometimes I can hear him lying there, talking to himself instead of sleeping. Oh well, nobody's perfect.
I usually start his wind-down sleep routine about 10 minutes before the start of his nap time, so it takes me about 5-10 minutes into his actual nap time before he falls asleep (15-20 minutes total).
Hope this helped.