I just bought minecraft and am havent the hardest time trying to figure out wtf is going on...I cant destroy any blocks. I am trying to destroy a tree with my fists but it isnt working, what am i doing wrong?! I have tried every bound key plus all 3 mouse buttons.

umm you need to hold down the left mouse button? With bare fists it could take a couple of seconds to destroy the tree, but you should notice the tree degrading as such