For those looking for a good place to take their kids to ride, I've been taking my boys (ages 7 & 9) to this new place close to Bonham called Bois darc (sp?) trails and they just love it. It has a smaller motocross track, a flat track, and a newer area that has a large table top and some whoops, etc. There are also some trails that looked well maintained.
The place is new and was not crowded (we were the only ones there the day we rode) so I didn't worry about my boys getting run over. It looks to be geared towards family riding, not really the bigtime, serious motocrosser, so I really highly recommend it for families and for beginning and intermediate riders.
The owners were on-site the weekend we were there and were pushing dirt around so I expect there to be more additions coming soon.
They work on a reservation system, so you will need to check ahead -- their website is:
http://www.texoffroad.com/