I know that it would be difficult, due to the immense ammount of functions, but www.php.net/quickref.php is amazing for php function references.  Is there anything like that? That quick reference guide got me through alot of learning issues in php.

http://www.msdn.com

I mean...

http://www.cppreference.com/

Providing you know the name of the function you're seeking info for, just type in on Google with a search like this: TheFunctionName "msdn.microsoft.com" and it should bring up in the top 1-10 searches a link to the function on MSDN's Website which is an excellent source of documentation (as LoRd pointed out) for C++ functions & more.