wxWidgets / wxPerl documentation

There is no wxPerl API document per se. The wxPerl API is described in terms of C++ in the following:
online wxWidgets documentation (2.6.3)
online wxWidgets documentation (2.8.4)

For the most part the wxPerl API closely mirrors the C++ API. When the C++ and Perl API differ, a wxPerl-specific note in the manual explains how the function calls translate to Perl.

The very short wxPerl manual explains in a little more detail the general strategy used in creating the wxPerl wrappers.

Tutorials

wxPerl tutorial
Jouke Visser tutorial on Perl.com
PerlMonks tutorial #1
PerlMonks tutorial #2
PerlMonks tutorial #3

Other

wxPerl Wiki