Ordered sets, pagenumbers and planarity

General bounds for the pagenumber of an ordered set are developed. One bound is derived by first showing that the maximum number of edges in the diagram of a planar ordered setP is 2v(P)-2-ht(P). A construction is given to show that the pagenumber of the product ofn chains is no more than 2n-2. Lastly, some open questions are discussed.