🚀 go-pugleaf

Lacking documentation for the notebook interface, I've been having a fun  
time trying to figure Mathematica out.

I have discovered a way to get the section and subsection headers (with  
the little square bullets) into my notebook; type in the text, and use the  
Style Inspector to change the style of the cell to "section" or  
"subsection" or whatever. This, however, is really a pain in the butt.

Is there an easier way, preferably with a keystroke, to automatically  
place a section cell into a notebook, or to convert an input cell to a  
section cell?

Any hints would be appreciated.

-Anthony