The Self Service knowledgebase contains information on Getting Started, Configuring Self Service Permissions, Using the Self Service Launch tool and and Navigating your way around.
The Developer Tool knowledgebase contains information on System Objects, Creating new elements, Creating New TABs and Forms, Modifying Form layouts, creating Workflow Tasks and Forms.
The Integration knowledgebase contains information on SOAP Integration, Making API Calls, Using Authenticating, Querying and Upsert Functions and Accessing the Gateway.