Re: Tennis elbow/clicking noise in elbow?
Hard to say. While overexertion is what usually causes tennis elbow, the fact that you're saying you hear some kind of clicking worries me. Naturally the elbow joint does make quite a bit of noise regardless of an injury or not, so this could be the case, but either way all you can do is at the very least give tennis a short break. Keep stretching it, rub the area around it and if it is bearable do some exercises gradually working your way back to normal strength and relief of pain. Naturally, if you play tennis long enough your whole arm will get strong enough and it should avoid getting such a type of injury which is more common for beginners since those joints and muscles are very unused to unique movement tennis requires.
E: Long story short, stop playing tennis a bit, check your pain and movement levels periodically, if you don't find improvement in a week, call a physical therapist/chiropractor.
Federer / Haas / Safin / Gaudio / Kuerten / Youzhny / Nadal / Gonzalez / Ljubicic / Hewitt / Soderling / Wawrinka / Coria / Nalbandian / Kohlschreiber