You navigate through directories in fman by pressing Backspace to go up, or by typing the first few characters of a file followed by Enter to open it. Tab switches from the left to the right directory tree, or vice versa. Multiple files can be selected with Space. On Linux and Windows, you can also use the Insert key.
By default, the main file operations are invoked via the function keys:
The following are also frequently useful:
The keyboard shortcuts can be customized to your heart's content. Please see this page for details.