Basic Concepts for those new to Service Catalog Requests:
Use the Proposal for New Service Request to describe what you want your form to look like and how it should behave.
Service Catalog Requests (have can produce one or more ITEMS that a client can order. These have the RITM designation in ServiceNow
EIntroduction to the ServiceNow Service Catalog
http://wiki.servicenow.com/index.php?title=Introduction_to_Service_Catalog