To start using speedbar use the command M-x speedbar <RET> or select it from the ‘Options->Show/Hide’ sub-menu. This command will open a new frame to summarize the local files. On X Window systems or on MS-Windows, speedbar's frame is twenty characters wide, and will mimic the height of the frame from which it was started. It positions itself to the left or right of the frame you started it from.
To use speedbar effectively, it is important to understand its relationship with the frame you started it from. This frame is the attached frame which speedbar will use as a reference point. Once started, speedbar watches the contents of this frame, and attempts to make its contents relevant to the buffer loaded into the attached frame. In addition, all requests made in speedbar that require the display of another buffer will display in the attached frame.
When used in terminal mode, the new frame appears the same size as the terminal. Since it is not visible while working in the attached frame, speedbar will save time by using the slowbar mode, where no tracking is done until speedbar is requested to show itself (i.e., the speedbar's frame becomes the selected frame).
The function to use when switching between frames using the keyboard is
speedbar-get-focus. This function will toggle between frames, and
it's useful to bind it to a key in terminal mode. See Customizing.