To save many hours of frustration, make Section 508 an integral part of the development process. All too often, Section 508 is first considered when looking at a finished product, when an evaluation tool can overwhelm the developer with errors and warnings.
To assist developers in making Section 508 an integral part of the design process, here are some helpful resources:
The Section 508 Checklist developed by the Applications Development Branch (ADB) is as much a help in development as it is an evaluation tool.
The Section 508 Living Examples section of this site provides developers not only with the explanations of the guidelines from the Checklist, but also some code examples of these guidelines at work.