Learn proper form for each exercise. It's very important to learn to lift properly, trying the different exercises you'll do in your workout with an empty bar, then moving on to the weighted barbell to make sure you're got the fundamental movements down.
- Consider consulting a personal trainer for guidance, at least when you're first starting out. It's very possible and in fact probable that you'll train wrong if you train without guidance, which can result not only in injury, but a huge waste of time and effort.