GCC function call library for Ubuntu documentation

[Forrest Myers]

I'm an old C programmer but most om my experience has been on IBM OS/2 
and Windoze. I'm new to linux. I'm looking for documentation on the 
standard C library functions for use with GCC and linux.  I used to have 
a very fine book from Microsoft describing their library calls for C but 
do not have it available. Is there online documentaion for the GCC 
libraries and if so, where is it?

I have the devhelp package installed and have lots of documentation 
under it but have not been able to find any C library information such 
as something as simple as fprintf(). Thanks for any help in point me in 
the right direction.

Forrest Myers AG4ND