How to Start Biking?

So, I ran my first marathon on May 31st. It was a huge struggle to reach that goal, but now that I am there I'm looking for my next goal.

I have some friends who ride mountain bikes -- and they've invited me to come out with them on Saturday on their next hill ride. Apparently, not everyone is a great rider, and a lot of the guys carry their bikes up the bigger hills. Should be fun.

Another option is to keep running. My wife has suggested a 5K mud run in Irvine. That might be fun with obstacles, walls, and lots of mud. At least I don't have to worry about getting a flat tire!