Current Perl documentation can be found at perldoc.perl.org.

Here is our local, out-dated (pre-5.6) version:

perlman:perltoot is a good place to start, and you can use perlman:perlobj and perlman:perlbot for reference. Perltoot didn't come out until the 5.004 release, but you can get a copy (in pod, html, or postscript) from http://www.perl.com/CPAN/doc/FMTEYEWTK/ .

Where can I learn about linking C with Perl? h2xs, xsubpp

If you want to call C from Perl, start with perlman:perlxstut, moving on to perlman:perlxs, the xsubpp manpage, and perlman:perlguts. If you want to call Perl from C, then read perlman:perlembed, perlman:perlcall, and perlman:perlguts. Don't forget that you can learn a lot from looking at how the authors of existing extension modules wrote their code and solved their problems.