If anyone wants to be a social media manager then where the best s/he can learn?

I guess anyone can be the best Social Media Manager where they can learn best through their own practice on Major Social Media Platforms including Facebook, Twitter, LinkedIn, Pinterest, Stumbleupon etc.
However, I suggest that at first, Social Media Evangelist should focus on 3 major areas including Facebook, Twitter& LinkedIn including : a)Facebook Business Page Creation & Setup and Page Maintenance, Group Creation, Connectivity, engagement of users on groups & communities, Event Creation on Business Pages.
b)Keywords Based Press Release on Twitter, Social Media Profile and link submission and sharing.
c)LinkedIn Company Page Creation, setup and its maintenance, Group Integration on your Company Page so users would love to engage on your page, Group Creation and Participation etc.
Have a Nice Day.
Syed Waqas Saghir Internet Marketing Expert, SEO Consultant, Social Media Evangelist.