Any of you participate in mountain biking? Now, living in IL, I can't really "mountain" bike, but we do have a few decent trails, but I've never really done it. I ride my bike around the city, and take my mountain bike when I go rock climbing to dick around, but never actually done real biking. I am just looking for another new way to be outside and be active in nature, and this seems a perfect addition to rock climbing. I checked online and found some trails that look like fun within decent distance.. and once I get the hang of it I can start to travel a bit more to trails in Michigan, Wisconsin, Kentucky, etc... Is there anything specific I need to know, or I do I just find a trail online and have at it? Are there silent rules or biking manners I should know about?