I have had three children and breastfed all of them for about 13-14 months. After I started giving them any solid food, my cycle started up not long after that.
If memory serves, they were all about six months old when they started any real sort of solid food ... solid food to the degree that they were breastfeeding less. They had had some cereal but nothing significant. So by 7-8 months, my cycle had kicked back in.
A caution: I was pregnant with my second when my first was nine months old. She started solids at about six months ... shortly after that my cycle resumed, and WHAM! :-) A blessing, but keep it in mind.