Buffer commands:
:bn => buffer next
:bp => buffer prev
:bwipe => clear file
:e filename => load a new file
Search and replace
:s,find-text,replace-text,
Pipe through tidy or other program
:!perltidy
Reformat a paragraph
:!fmt -70
Show line numbers
:set number
:set nonumber
Completion:
ctrl-n
Searching:
/ - search
* - searches for the word under the cursor
n - next match