Identify the level of experience you are looking for prior to writing an ad or sending out introductory letters. If your cast is comprised of amateur actors, for instance, Broadway credentials and a mantle full of Tony awards aren't required. Conversely, a large-cast musical on a professional stage is likely to be well beyond the abilities of a first-time director who has previously only done script-in-hand readings. Other factors to take into consideration are the salary and/or percentage you can afford to offer as well as whether you are searching for someone to direct one specific show or become a permanent member of the production team.
Advertise for the stage director position in local media if you are seeking someone who already lives in close proximity to the community where the theater is located. If you want to broaden your search to a regional or national level, post your ad at theater websites such as American Theatre Resources, Backstage.com, Theatre Communications Group and Theatre Resource.com. In either case, specify whether applicants should mail a portfolio of their work along with reviews, apply online or send a cover letter requesting an interview.
Attend theater performances and read play reviews to familiarize yourself with the work of directors that interest you. If the director is on the premises after a performance, introduce yourself and request an upcoming time to chat. If you like what a review has to say, send the director a short note or email, referencing the production and asking if she has interest in working with you.
Ask for advice and recommendations from your fellow theater associates including actors, technical personnel and theater owners. Use word-of-mouth publicity to let prospective directors know that you are looking to hire someone. You may also want to consider talking to the theater arts department instructors at nearby colleges to see whether there are promising students qualified to take the helm of your productions.