Panel plugin howto?

Hello!

I'm interested in making plugins for the xfce panel, but there are a few 
questions/obstacles i need help with. It would be perfect is someone 
could make a little howto to get noobs like me started :)

The howto could handle stuff like autoconf (perhaps this is OT, if it is 
i'd like to know where to learn it).
Other things could be a more informative example than the sample plugin.
Perhaps a step-by-step guide on how the sample plugin was created?

Oh, another question.. is C a must, or can i develop in C++ aswell?

I realize that making such a howto could take a lot of time, but i think 
that more people than me would like to get started.

Regards,
Erik