You can check the GeoCAT User Guide to guide you in the usage of the tool. The User Guide includes Help, Data layers, FAQs, Links, Documents and a Glossary to help you make the most of GeoCAT.
If you think you will become a regular user of GeoCAT, you will find a lot of useful information in GeoCAT Mailing List. Subscribe to it and get in touch with us and other users.
Do you have any doubt, problem or suggestion about the tool? Contact us.