in reply to Learning about OLE and Win32 with Perl.
Along with the online documentation mentioned above, consider the book you mentioned. I own a copy of "Win32 Perl Programming: The Standard Extensions, 2nd Edition" and carry it in my laptop bag. I looked to confirm that chapter 5 is dedicated to OLE. Of the 65 pages in chapter 5, approximately 7 are dedicated to Events. In addition to OLE there are several other valuable chapters on accessing dll files and working with win32 modules in general.