Today is the last day to register to vote in next month's election (official date anyhow, there will still be places you can register, apparently, until the last week of October). In Carbondale, you can register at the City Hall/Civic Center.
Incidentally, as of yesterday, 35 people had picked up petitions to get on the ballot for either mayor or city council. You don't have to decide when you pick up the ballot, just when you turn it it, so there's no good idea as of this date, how many people are running for mayor and how many for council. However, it's a good bet that, given the amount of interest and the number of ballots out there ( and how few signatures it takes to get on it), we will see both a primary and a general election.