99designs has an intuitive design posting process that helps you present your vision to designers in an organized fashion. Visions can be subjective and their process helps you get a much better result than a typical graphic design job posting. Non-designers usually have no idea how to explain a concept to a graphic designer and I like the questions 99designs asks you to define your design brief. Many other crowdsourcing websites leave your design description wide-open which can lead to you not getting what you want.