NewInstance

Apart from the basics, which you should know to use vim, there are many useful commands that I always forget, and every time I need to search on Internet.
Here's my very little cheat sheet.

Enabling/Disabilng row numbers:

:set number
:set nonumber

Enabling/Disabling Syntax Highlighter:

:syntax on
:syntax off

Text search tips (where "text" is the text to search)

search forward:
/text 

search backward:
?text 

search case insensitive:
/\\ctext

Search and replace (OLD to NEW):

First occurrence on current line:
:s/OLD/NEW

Globally (all) on current line:
:s/OLD/NEW/g 

Between two line 123 and 345:
:123,345s/OLD/NEW/g

Every occurrence in file:
:%s/OLD/NEW/g 

Move to the top and to the end of the file:

move to the top of the file:
:0 

move to line 123 of the file:
:123

move to the end of the file:
:$

Maybe some new tricks will be added. (Post your suggestions in comments!)