7 a.m.-8 p.m., your local polling place, boe.baltimorecity.gov, free (technically, but think of all the sacrifices made to grant you this right).
Go vote already! Exercise one of your most important rights as an American citizen. Seriously, there’s a whole mess of people running for mayor and there’s going to be a lot of turnover on the City Council, and since Baltimore is a one-party town, this primary election basically determines who runs the city. Put down the paper and go vote. Right now.