OK, since it's been YEARS since I have been actively riding a bike, I figured I needed to get into shape before I really took on some serious trails. I went to Alafia and rode Rock Garden and Pine Forest, and I have to say I was pretty beat up. I am active, lift weights and run, but this is a whole new experience for me. I came upon a couple serious hills at Alafia, and have to admit I wussed out and walked up them-it was more or less due to lack of confidence over keeping my balance and pedaling like nuts to get up them-they were pretty darn steep (it wasn't Rock Garden, but one of the more difficult trails, can't remember the name). Soooo. I started off easy by doing some intervals on the Suncoast Parkway, and plan on doing this 3x a week.
5 minute warmup/pedaling light
2 minute moderate work/ pedaling at about 80% of max, medium gearing
1 minute hard work/pedaling 100%max at hardest gearing
Repeat the two minute /1 minute work sets for 4-5 times
5 minute cooldown
I plan on working up to 1 minute rest sets and 2 minute hard work sets in a few weeks. My legs are burning pretty good today.
My goal is to get into good shape enough to handle the altitude and harder trails out west; I plan on making a trip to Moab/New Mexico and Arizona next year around May or September. I also plan on hitting Alafia and Morris Bridge frequently to get some skills in the riding department, which I have absolutely none of at this time

I have never ridden dirt trails before- I was always a concrete rider, so this is a whole new animal for me.
Any other training suggestions? I also hit the weights and do circuit training 3x a week as well. I have good cardio, I'm just a little weak in the coordination/climbing and a little nervous in the downhill/excess speed category. I know those things will simply take some time and a lot of practice, but if there is anything anyone can hook me up with I'd appreciate it. I also plan on taking the beginning mountain biking classes I have seen offered on this site as well.
Thanks in advance!