[Koha] Any guides to working with CatExpress subscription service?

Hi everyone, Cataloging newbie here. Please excuse the elementary nature of this question. My client is using Koha, would like to start using OCLC's CatExpress subscription service (which downloads the records the next day). Are there any guides to setting up Koha to work with these CatExpress files, and/or workflow examples, out there? I am especially concerned with getting the 856 URI properly handled. Thanks, Steve