R.G.
Sleep is such an important thing for growing children - good for you for realizing that!
This is just my suggestions based on what worked for us... :)
Check out the book "Healthy Sleep Habit, Happy Child" by Weissbluth. Fabulous for getting children on a routine. I'd recommend YOU setting the schedule for awhile, and err on the side of being too early rather than too late with the timing of naps/bedtime. For a 6 mo. old, Weissbluth recommends a wake time of 6-8AM, morning nap starting about 2- 2.5 hours after that (9-10), an afternoon nap starting between 12-2 and a third "catnap" for some children. Bedtime between 6-8.
Our routine for DD at 6 mo....
7AM wake, nap at 9AM for 1.5-2 hours; nap again at around 1 PM for 1.5-2 hrs; 45 min nap at around 5PM; bedtime around 8PM. We dropped the third nap at about 8 months and then bedtime moved more toward 7PM.
I controlled her wake times to "protect" her sleep schedule. It was a solid 2 weeks of work at 5.5 months to get her on this routine, but it was totally worth it. For 2 weeks, one of us was home at all of her sleep times - no catnaps in the car, etc. She became a fantastic sleeper. She's 2.5 now and is a great sleeper who loves to be in her bed!
Take care,
R.