:NERDTree, :NERDTreeClose, and :NERDTreeToggle
map <F2> :NERDTreeToggle<CR> # maps :NERDTreeToggle to <F2> within .vimrc

All other keyboard shortcuts can be found by pressing ?. It will open a special help screen with the shortcut listings. Press ? again to get back to file tree.

* Use <C>+w to switch context between file and nerdtree
*  Use the natural vim navigation keys hjkl to navigate the files.
* Press o to open the file in a new buffer or open/close directory.
* Press t to open the file in a new tab.
* Press i to open the file in a new horizontal split.
* Press s to open the file in a new vertical split.
* Press p to go to parent directory.
* Press r to refresh the current directory.