My pedi told me between 9 and 10 months to start my little girl on 3 meals a day. This seemed earlier than what she told me with my son, but I went ahead and did it and we have been on 3 meals a day for almost a month now. About a week after we started was the first time she slept through the night, so that was a plus. She also told me to go ahead and start her on some dairy, Yo-Baby Yogurt, string cheese, and whole milk at 1-2 oz every couple of days...and start her on more solid table foods that we eat like shredded turkey from the deli, chicken breast, and red meat. We have also done this and she is a totally different baby...a lot more active, playful with my 2YO, and happier all around.
I decided to follow the 3 meals a day at 9 months because my little girl was so dependant on bottles of breast milk and/or formula. This has cut the 8-10 bottles down to 4-6 a day and rarely does she finish one where she does not leave an ounce left over. To me this is going to help in weaning her completely from the bottle at the age of 1.