Define the theater hierarchy. Decide if you want to run the theater company by yourself or if you want a board of directors to work together on artistic, administrative and financial decisions before you start. Look at the mission statements and bylaws of other community theater groups and follow the structure of the ones that appeal to you.
Develop your identity. Think of a name and approach for your community theater. Depending on the location of the theater and proposed audience, you may want to feature dramas, comedies, classics, avant-garde performances or all types of plays. Design a logo and write a marketing plan, and start advertising once you've planned the first season.
Consider financial options. Incorporate as a non-profit if you will feature experimental plays or have the time and inclination to deal with paperwork, extra bookkeeping and government regulations. If you do decide to operate as a non-profit, your company will be eligible for special grants. Remember that you'll have to abide by stringent rules if you want to remain a non-profit.
Target a specific audience. Once you've settled on a name and written a mission statement for your community theater, start advertising to that market segment (i.e. middle-aged suburban couples, bohemians, twentysomethings) by using mailing lists for that demographic and placing advertising in publications and websites aimed at that particular group.
Hire an office staff. Depending on the size of your productions and the intended audience, you might need to hire one assistant or an office staff with a bookkeeper, publicist and secretary.
Rent an appropriate venue. Consider insurance, location, acoustics and how many patrons the space can accommodate.
Learn how to secure rights. Check with the playwright or his agent to obtain rights to perform the play for a specific time. If you wish to feature an original play, you'll need to write a contract with the author.