You need to be a member of Sasquan, this year's worldcon, to vote on the Hugos... but even if you are unable to attend, Supporting Memberships are available that will allow you to vote. If you have not voted the Hugo Awards before, please note that it is an "Australian ballot," a preferential system whereby one ranks the nominees. You don't just vote for one. You can rank NO AWARD as if it were any other finalist; ahead of some nominees, behind others.
You can sign up to buy one at https://sasquan.swoc.us/sasquan/reg.php In addition to voting privileges, a Supporting Membership will get you the convention's program book (usually a handsome item, though it varies from year to year) and other publications.
The ballot is here: http://sasquan.org/hugo-awards/voting/
You can also sign up as an ATTENDING member and actually attend the convention, which is the course I strongly recommend for those who have the time and the money. Cons are fun, especially worldcon; that's what they are all about. Reading, panel discussions, the art show, the dealers' room, the masquerade, filksinging... all sorts of great stuff goes on. Something for all tastes. And EVERYONE is welcome, despite what you have heard. (Just don't be an asshole. Assholes get welcomed too, but the welcome wears out more quickly).
Both supporting and attending members get an electronic "Hugo packet" that will enable you to read many of the works nominated for this year's rockets.
FILE 770, which has been doing an exemplary job of reporting on Puppygate, reports that Sasquan memberships continue to climb, and that more than 2300 Hugo ballots have already come in:
Who are all these new Supporting Members? Are they trufans rallying to the defense of one of our field's oldest and most cherished institutions? Are they Sad Puppies, Rabid Puppies, Happy Kittens, Gamergaters? Are those dreaded SJWs and ASPs and CHORFs turning out by the hundreds and the thousands? Are these the Neo-Nazis and right-wing reactionaries we have been warned of? The truth is... no one knows. We may get a clue when the ballots are opened and counted, but even then, the numbers may well just say, "Answer cloudy, ask again."
All I know for sure is that every vote will count.
Once again, balloting closes at midnight on July 31. And it would be best not to wait until the last day to vote, since there is a very real danger that Sasquan's servers could be overloaded. Even if you haven't finished all the reading -- and I do urge everyone to read the nominees -- you can cast a partial ballot today, and go back and revise, add, delete, and change as many times as you want between now and July 31. No votes will be counted until the deadline.
Let this be fandom's finest hour. Vote.