Recently there has been an increasing emphasis on co-teaching in schools. General education teachers and special education teachers are paired in the classroom to support all students. The nature of the relationship between these two teachers is often described as a "professional marriage." This article provides specific advice on how co-planning time can be effectively used to foster the necessary foundation for co-teaching success. This advice encompasses standards, assessment, accommodations, instructional strategies, and logistics. A checklist for ensuring that both teachers have identified and communicated relevant information in these areas is also included. This checklist is a useful tool that any co-teaching pair can easily incorporate into their planning process. (Contains 2 figures.)