Monday is the deadline to register to vote in the general election.
If you don't get it done by then, you're going to be out of luck in November.
You can register to vote online, you'll have to go through several steps on the Arizona Secretary of State's website.
You can also register to vote in person at the county recorder's office. In Maricopa County, the office is located in downtown Phoenix; in Pinal County, the office is located in Florence.