Post or not post

I'm a graphic design student, I actually have some cool stuff that I done to share with people, but the problem is DevianArt isn't suited for design. 
So I was thinking about creating a Behance account that is actually more professional, more suitable for design and going to be just like a portfolio.
And now have several questions:
- How does Behance work, does someone know? Can you explain to me?
- Should I continue to post graphic design stuff on my account?
- Should I get a Behance?
- Does it coast?

So yeah... 

If... Just if someone will reply to one or many of those questions, I'll be really grateful.