How to contribute to this list

[Olivier]

Hello,

I don't know if I'm currently using the best channel to ask it, but I
would be very happy to contribute a couple of hours a month to Debian.

As I'm specifically interested and involved in VoIP, I'm asking here
how I could be useful.

Are there some tasks I could handle ?
At the moment, I'm using Debian daily for several years now, but I
don't know much about Debian inner tools and process.

Cheers