Beginner with ABAP WEBDYNPRO

Hi all,

I am working in SAP EP for 3.5 years now.

I want to learn abap webdynpro,

Kindly let me know.

1) How and froem where to start with?

2) How much abap skills required to learn abap webdyn pro?

3) Kindly provide relevant docs/link.

Thanks,

Ravi