I concur. Fox Valley and Lincoln Trails are great places for beggining riders.
Since you bought Honda's, take the time to read every word in the booklet they provided with the bikes. It is to teach parents how to deal with brand new riders and has some of the best info you can have.
It is for the kids, but parents should heed every word of advise in it.
So often a dad gets overly excited about his kid riding and trys to give them too much to handle in the first couple of outings. This can ruin a kid fast.
Only a crash or two. without proper guidance, and a kid may not want to be a part of what they see as a painful ordeal.
Take your time, and teach the kids proper safety first thing. Plant all the rules, nurture them, and you will have great times ahead.
Hurry things and get overly excited without proper preparation and be sourly dissapointed.
I personally would never take a new rider to ANY track or offroad facility. Granpa's field is well made for those first few rides.