did u add to your gplib directory : libgpfont16.a ?
how many surfaces do you have ? Did you try : GpTextOut16(NULL, &gpDraw[0], 10, 10, (char*)"some test text...", 0);
the gpfont16.h must be with all the other gp include file.
Have you modify your makefile to compile the libgpfont16.a ?
like...