Learning VoIP and Asterisk

Hi.

I wanna learn Asterisk as a professional. I know, before it i should read something about VoIP…

So, would you please tell me where should i begin from?

Please give me some learning materials. books, video training and etc.

Best regards,
Amir.

i think you should take a look at this book. this is just one many… Asterisk: the future of telephony this book should answer some of your questions…
by Jim Van Meggele