Cataloguing is the process of adding records to eHive for the items in your collection. You can add records for a variety of different kinds of items.
The help here is to guide you through cataloguing in eHive. If you're new to cataloguing, or would like to learn more about the process generally, there are a number of other useful resources available online. For example, The Small Museums Cataloguing Manual from Museums Australia (Victoria) and A Guide to Describing Cultural Works and Their Images from CCO commons.