First, find yourself a good quality MMA gym. If there aren't any in your area: look for a Brazilian Jiu-Jitsu school, a kickboxing school, and/or judo/wrestling school (now we're playing mix-and-match). A solid MMA gym will include something for each of the basic three fighting necessities (stand-up, takedowns, and grappling).
How often you train is up to you. I train 5 days per week, and take the weekends off to make sure I have family time. Your bodybuilding should come second (depending on how serious you are about MMA) since the two don't always work together. The strength you're accustomed to from lifting, will quickly wear out when your grappling, but it'll come in handy when you're wrestling. Big bulky muscles also tend to slow down your speed for striking as well. I'd recommend training only MMA for a few weeks and take some time off from lifting (to let your body acclimate to the rigors of training MMA) then slowly add back in the lifting. However, instead of going for bulk like bodybuilding, you'll want to start gearing your workouts towards functional strength (check out http://www.rosstraining.com
to see what I mean).