You really shouldnt have more than two cups of coffee a day, the caffiene in a cup of coffee is close to 200 mg. Tea it depends on though, if its caffinated tea i would keep it between two to three a day, they are similar to sodas and sodas contain almost 50 mg of caffiene. I wouldnt exceed 200 mg a day, but of course less is always better.
Two cups is good but if you are a coffee freak try mixing some decaf in your morning brew. Buy good decaf since the cheap decaffienated coffee can taste like an old tire.
i say no more than 3 unless its decaf