Develop your routine. Write several minutes of dialogue and pick out the best jokes and routines to fill a five- to 10-minute set. Start off performing in front of a mirror so you can see what you look like while performing. Gather small groups of family and friends over and perform a few minutes of your routine to get their reaction and even advice, if necessary.
Create a video or DVD of your routine. Go to your local comedy club during open-mic night and perform your stand-up routine. Have a friend film your routine -- preferably more than one time so you can edit it to your benefit. Burn several discs that you can send out to prospective agents.
Develop a list of talent agencies who work with comedians specifically, and actors in general, either those in your geographic area or where you plan to move if you decide to try your luck in a major market such as Chicago, Los Angeles or New York. Search physical or online directories; numerous acting websites, such as the Association of Talent Agents and Screen Actors Guild, have lists of talent agencies.
Send out copies of your stand-up routine to the talent agents you have selected. Include information about yourself and why you want to be a stand-up comedian, such as your influences, both professionally and personally. Include a resume that lists any comedy work you have done, both stand-up and as part of an acting troupe. Add a headshot photo of yourself as well. Follow up a couple of weeks later with a phone call to see if there is any interest in taking you on as a client.
Contact the talent agencies again once you have scheduled another comedy gig at a local club. Arrange for free tickets for any agents, or their assistants, who may be interested in seeing your act.