gcc, a librarian?

Hi I have useful.h, useful.cpp. how can I create my own library for future linking to other projects I write? any link to read would be good. thanks See the all-new, redesigned Yahoo.com. Check it out.

adding a dir to the search path

HiI am trying to link the gsl library to my c++ project. using debian/testing 2.5.16 and g++ 4.0.3-4the instruction in the library is:If the directory is not installed on the standard search path of your compiler you will also need to provide its location to the preprocessor as a command line flag.