Mintty comes with git for windows. It comes with an ssh client so you don't need putty. I found mintty to be easier to work with.
Setting term to be
xterm-256color gives mouse support for vim, tmux, etc. Originally it was
xterm and it didn't work.
In ~/.tmux.config set
set -g mouse on will enable mouse support for selecting pane, resizing, etc. See here.