You need to be a supporting or attending member of either the forthcoming worldcon, Denvention 3, or the past one, Nippon 2007, to nominate. If you're not a member, however, it is easy enough to join, and supporting memberships -- for those who can't make the con -- are cheap enough.
Nominations can be made online at Denvention's website at
Nominations must be in by SATURDAY, MARCH 1 to be counted.
These days there are dozens of different awards being given for SF, fantasy, and horror, and all of them are nice enough, to be sure, but the Hugo is the oldest and far and away the most important. This is the one given by the READERS, not by some hand-picked jury, and the more people who participate in the process, the better. Not enough people vote for the Hugos, sadly, and far fewer bother to nominate... which is a shame.
So don't miss your chance to take part. Go ye forth, nominate, vote.