So what is DOMs? Well delayed onset muscle soreness is the stiffness and sometimes pain you feel, normally around 24 hours after a bout of exercise that is either more demanding than you may have be used to, or just different exercise! Sore muscles after exercise are very common and not a reason to panic, so don't rush to the doc's.
Sore muscles are not a bad thing in general, it lets us know how hard we have worked, and as long as it isn't at the point you cannot function, is often seen as a trophy from the previous days workout.
So what can be done? The trick is to keep the tight muscle mobile, sitting doing nothing for as little as fifteen minutes can result in the muscles tightening up again. Also, drink plenty of water, this helps flush toxins from your muscles as they repair themselves. As long as you can still move, and have had a day off training further exercise will help release the muscles again, but care should be taken to keep your form as good as possible to prevent injury, a lot will depend on how stiff or sore you feel! If you have access to a foam roller this can be used to massage the muscle prior to more exercise. I recommend holding on the most painful spots for 30 to 90 seconds, rather than rolling back and forth.
When should you NOT train? As I said there is no real problem training 48 hours after a session, but if you are in sever pain and feel very inflexible compared to normal leave it another day!