Step-by-step tutorial with detailed instructions is a good place to start your DipTrace experience. The first part of tutorial will show you how to design a simple schematic, convert it to PCB and get manufacturing files. The second part will teach how to create new components and place them into Schematic and PCB Layout. The last part will demonstrate the use of different program features, which may extend your design capabilities and were not touched while making simple project.
DipTrace comes with vast component and pattern library sets. Pattern libraries have a naming system, where each pattern name contains information about pattern type, size, pads layout, and paramaters, etc. This PDF document describes the meanings of the pattern names and will help you to understand them.