The 2014 rulebook (can be downloaded here) is the newest one. there is a printed 2015 rulebook. But the only difference from the 2014 RB is an updated LoF chart at the end of it.

The next rulebook is said to be released sometime later this year.

Specifically, August 30, in the Mighty Thor starter.

I have that i'm looking for an updated version of this

http://heroclix.com/wp-content/uploa...ge-2013-02.pdf

There is no such document. All erratas, clarifications, and other such materials are now on the WizKids Information Network (WIN for short).

http://win.wizkids.com/bb

This thread: http://www.hcrealms.com/forum/showthread.php?t=572888

May also help you in using the above resources and understanding how to navigate them.