In general if you're just beginning to look into this I'd advise you to look at Inline::C, which allows you to embed your C in Perl and access Perl's data structures in a nice and simple way. The Cookbook which comes as part of the distribution is a nice tutorial on how to do the basics.

..oh, and I'd wish you luck, and point you at the Perldocs on perlguts and perlapi, they are most useful.