The UK Serials Group report Link Resolvers and the Serials Supply Chain (May 21, 2007) covers the components of the OpenURL resolving equation - OpenURLs, resolvers, Knowledge Bases, and a critical component: the data provided by publishers.
In a perfect world, automated and entirely correct data would flow from publishers directly into our resolver knowledge bases. It is not a perfect world.
The report discusses some of the major issues and proposes some solutions as well as areas for further research.
One of the main things I get from it is that everyone involved needs to understand how resolvers work, and how correct data benefits everyone in the "serials supply chain," from publisher to end user.