Most of the trails are small double track limestone loops, map found here http://www.ontarioparks.com/english/pdf/bron-day_use.pdf or you can get a printed copy from the main gate house at the entrance.
If you look around you can find some OK single track trails that head down the slopes to the 12 mile creek, good little climbs to get back up. If you are heading in with your car there is a fee to enter the park which I think is $10.75 per car. I can honestly say that if you are heading here just to ride the trails the car entrance fee is not worth it, but if you are planning to spend the day seeing all Bronte has to offer then it's more then worth it. You are also allowed to bike or hike in for $1.00 per person.
Watch out for dog walkers this place is a haven for them! Bronte is the perfect place to burn a couple hours riding with the little ones, nothing to difficult or technical. There is a bunch of other things to see and do while you are visiting Bronte Creek, animals, play barn, nature center and century old farm house. You can easily fill a day exploring this place on bike and foot.