There are many tools available for assisting you in creating accessible content. Much of it is freely available, and NC State has also purchased licenses for several commercial applications.
The IT Accessibility Office maintains a list of recommended software for testing Web accessibility, much of it available for free.
Licensed Software Available at NC State
SortSite - an application for for evaluating the accessibility of Web sites
MathType Equation Editor - an application for creating accessible math for the Web
LecShare Lite - an application for creating accessible Web pages from PowerPoint