Q: If my muscles are sore (the next day) should I work out anyways or wait for it to stop?

A: You shouldn't work out the muscles that are sore, but you can work out other muscles. For example, if your legs are sore you can still work out your chest. That's why 'split' weightlifting programs are popular -- they split up your schedule to work out different muscles on different days allowing you to be sore in one muscle group but still working out another. You can find several sample split routines in my Weight training article.