The last day for candidates to withdraw is April 3.
The last day for voters to register is April 17.
Voters must be a city resident for at least 21 days, and can register either at city hall, the Havre de Grace library, the board of elections in Forest Hill or online at http://www.elections.state.md.us.
Applications for absentee ballots are available at city hall until May 1.
Candidates must pay a $50 filing fee, be at least 25, be a U.S. citizen for at least 10 years before the election, be a qualified voter and be a Havre de Grace resident for at least two years before the election.
Scarborough, 47, is a newcomer both to the election and to Havre de Grace.
He moved to the city in 2009 from southwest Baltimore with his wife and three children and is now a stay-at-home dad.
Scarborough is a disabled veteran who has been involved with the American Legion and chaired the residents association in Bulle Rock, where he lives.
On running for city council, he said, "I think it's something where I have been involved in a lot of organizations, [and] I can serve all of them better on the council."
"The one thing I have noticed is, it's a small town but it's not as small as the town I grew up in, Pendleton, Ind.," Scarborough said. "A lot of times, you may be able to get more done in a small town than in a big city."