If you want some ideas our local "little kids" league here in Oklahoma is the Indian Nations Football Conference. Web site is
http://www.youthfootball.com/index.asp
This is a mighty mite (1st/2nd grade) to 7th grade (for some schools) league that has over 250 teams. The high schools are very good at supporting the league in facilities amongst other things. By laws are on the site as well. Give the office a call if you have any questions.