There are several OHV clubs down in the Boise area that I am sure schedule rides for varying levels like our club does here. We are up north near Spokane so we've switched to sleds (finally today with the new snow).
As a new rider, you may be interested in joining one of the local clubs to help protect your right to ride. Our club has a great working relationship with the local Ranger Districts up here and it really helps give us a voice in how the public lands are managed. We have trail maintenance work days, meetings with the Rangers and try to hold monthly club rides. It's a great way to meet riding buddies, learn new skills, try new riding areas and keep informed on what's going on with the public lands. I know there are some Wilderness proposals threatening in your area that the Idaho Trail Machine Assoc. and other clubs down there are fighting to prevent.
I suggest you get involved - the earlier the better because once you get hooked on riding, you won't want to give it up!
Here's a link to the Treasure Valley Trail Machine Assoc site:
http://www.tvtma.com/
and the Boise Ridge Riders site:
http://home.off-road.com/~kjhbrr/
Good luck and if you need any more info just ask! There's also a few DRN members down in your area too but they are still sleeping it looks like. :laugh: