New to the rec. center... machines?? Clueless. HELP!

I've taken a few steps back in my progress, but I have taken a few steps back and want to get back on the weight-loss train. So, I started going to the rec center at my college before Christmas break, and I realized that I really have no idea what I am doing there with so many weights and machines. I'm familiar with calisthenics since I've always just exercised at home, but I now have a whole rec center to take advantage of that is a 5 minute walk from my dorm! I would love to incorporate lifting into my workout, but I am kind of clueless as to what I should be doing. I was hoping that someone could give me a general idea of some sort of routine I could start off with.

I'm planning on going to the rec. on Mondays and Tuesdays, taking a break day, and then going back on Thursdays and Fridays. I was thinking about taking about an hour and a half; half cardio and half weights. I know that it's good to assign certain body parts to each day, like back and bis to one day, chest and tris to another, legs to another, etc., and that a little ab work each day doesn't hurt. I just am clueless about the machines, reps, weights, etc. :P Could someone maybe give me a suggestion, possibly a skeleton of a simple routine to start off with?