Who to vote for in Witness Voting? (I am coming back after a LONG while)

Hello Everyone!

So many things seems to have changed.. Will have to learn it again..

How much power do I have? What am I worth? How can I promote my articles? How to promote other people's artcle that I like here?

Also, who should I vote for in "Witness Voting"? I have my 30 votes but I don't want to waste it

What are the advantages/disadvantages?

Any help please?

Regards
Amanda