很 = very
太 = too
The use of the two Chinese adverbs are very similar with the ones in English. Sometimes 太 is more than 很 in the degree or extent to describe something.
你人很好. You are very nice. (You can also say 你人真好)
你人太好了!
What a nice man you are!
你人太好!
(When saying it, there seems someting behind that. Maybe because you are so nice that you are cheated by someone).
你很瘦. You are very thin.
你太瘦了. You are too thin.
他太瘦了以至于他搬不动那个箱子. He was too thin to move that box. (Here you shouldn't use 很)