This is the first of five papers that construct an isomorphism between the embedded contact homology and Seiberg-Witten Floer cohomology of a compact 3-manifold with a given contact 1-form. This paper describes what is involved in the construction. † Supported in part by the National Science Foundation 1. If Σ ∈ M 1 (Θ -, Θ + ), then ∪ (C,m)∈Σ C is an embedded, pseudoholomorphic subvariety.