You can't go too far wrong when you're just beginning, as long as you try to learn as much as you can from reading and experienced people. But the real learning comes from doing. +1 for starting with light, comfortable weight, and read as much as you can about proper form. I would recommend the same as above poster of trying to lift 3 times a week at first, and focus on the big compound lifts that work your whole body - squat, deadlift, overhead press, and bench press. They can be done with barbells or dumbbells, just keep the weight light at first. Take little videos of yourself doing these lifts, and compare them with strict-form videos online that have a lot of positive feedback. Once you've experimented a little bit yourself, see if you can't find a gym that offers a free promotional training session, or just pay for a session or two so that someone experienced can really tell you how you're coming along. Even better if you have an experienced friend who can go with you a bunch of times. 3 sets of ten repetitions is a pretty standard starting regime, and can help get your body accustom to the various movements.
Keep in mind a few simple ideas:
1. Work out your body, not the weight (choose a weight that you can lift with proper form safely, while getting the full range of motion)
2. You can always learn more, and you can always improve
3. Proper diet and sufficient rest come first