How many votes are we afforded in the moderator election?
StackExchange final elections are administered using what is known as the Single Transferable Vote method, specifically the meek STV algorithm.
Basically, each user gets exactly 1 vote. However you are allowed to select three candidates in order of preference. Your single vote will be divided up between these candidates in whatever fashion is most advantageous for your first selection, second selection and finally third selection.
If your first candidate of choice gets more than twice as many votes as anybody else in the election, he really only needs half of those votes to win. In that case 1/2 of your vote will be used to make sure your first choice gets elected, and the other 1/2 will be used to get your second choice elected. If that works out and there is still leftovers, it will be parceled out to your third choice.
In the event that one of your selections is un-elecetable (meaning even with all the people that voted for them using their full vote value won't put them ahead of anybody) then the candidate is eliminated from the race and your vote applied to the next candidate on your selection list.
In the end you have the power of 1 vote, but it is distributed across three selections in a mathematical way that is most likely to get your selections elected in order of preference.
Before the actual final election as described above, in the event that more than 10 candidates have been nominated, there will also be a primary phase. This phase works just like the votes on answers. Eligible voters get to vote up or down on as many of the candidates as they feel like. The result is to sort the candidates by some rough gauge of electability. At the end of this phase the top 10 entries by final vote score move on to the actual election phase and enter the STV system.
The answer is listed on the right sidebar of the election page:
Each community member has 3 votes. Please cast your votes in order of preference, starting with the most desirable candidate first.