You get a total of 10 votes to use. You can use up to 3 votes on any one idea.
You need at least 1 vote from your "bank of votes" if you want to create you own idea for others to vote on.
The votes you've used on any one idea will returned to your "voting bank" once that idea has been "closed" by us.
For a more detailed explanation, go to http://feedback.uservoice.com/knowledgebase/articles/63-how-does-voting-work-