From The Jargon File (version 4.4.7, 29 Dec 2003) :
STFW
imp., /S?T?F?W/
[Usenet] Common abbreviation for ?Search The Fucking Web?, a suggestion
that what you're asking for is a query better handled by a search engine
than a human being. Usage is common and exactly parallel to both senses of
RTFM. A politer equivalent is GIYF.