Start slow...low weight, low # of sets...just to get your body acclimated to lifting. Don't just do chest and arms, you gotta do the whole body. Chest, back, shoulders, biceps, triceps, abs, legs.

Chest: Incline bench/dumbbell press, decline bench, flat bench/dumbbell press, dumbbell flyes

Biceps: Dumbbell curls, hammer curls, barbell curls

Triceps: Closegrip benchpress, kickbacks, skull crushers, overhead dumbbell extension

Shoulders: upright barbell rows, dumbbell/barbell shrugs, front/side dumbbell raises

Back: Bent over barbell/dumbbell rows, deadlifts, pull ups

Legs: Squats, calf raises, stiff leg deadlifts

Abs: crunches, bicycle crunches, side bends with weight, leg raises, reverse crunches

Obviously these are just some of the exercises you can do...but they should all be something that you can do with a basic free weight setup. I would start by picking 2 workouts from each muscle group to start with. Do 2 sets of 10 reps after warming up. Once your body is used to lifting weights (probably 2 weeks) then add another exercise and another set. Figure out how many days you want to work out, and plan a routine from there.