Google is your friend. First step. Lots of info available in the web but at some point you'll have to start talking to real live humans. What humans? As a start go to another market in which you would not be competing and befriend a cigar shop owner. One visit won't do it. It will take time. Everyone likes to talk when someone expresses interest in what they are obviously proud of. Spend time talking to people already in the bidness.
Another human to talk to is cigar company reps. Might even find out they have programs to encourage development of new outlets.
Third suggestion is to look for franchises opportunities. If its a good company they do the marketing and you do the operations work.
One factor to remember. All storefront businesses are challenged by internet sales. IMNSHO cigars are quite likely to be challenged by internet operations. Black Cat Cigars is in downtown Philly but have managed to develope an extensive internet operation
http://www.blackcatcigars.com/ . Another operation that combines storefront and internet is JR Cigars.
http://www.jrcigars.com/ In both cases they supplement foot traffic with internet sales.
Good luck.
One other thought. Software exists to help you step through a business plan. A business plan will not guarantee you success. What a business plan does is force you to ask the questions necessary to have a chance to get a business up and running. A large percentage of a BP is nonsensical BS but the very act of asking then answering the questions is of value.