Is this your first time on the Toolkit site? The First Time Users page features a brief overview of the Toolkit web site and how it might meet your needs. You can also find general information regarding the site and its background, in the About section.
The Tool home pages contain detailed technical information about each Toolkit tool. User manuals, tool publications and worked examples can also be accessed via the Documentation page.
The Forum is a good place where you can contact other registered users and ask for assistance.