I can't seem to download the supplementary materials (score sheets, profiles, meal guides, etc.).

The scoresheets and other supplementary materials are "pdf" files, the most common format for Internet documents that are meant to be printed. The most popular program for opening them is Acrobat Reader, which is available free from many places on the Web, including Adobe's site: www.adobe.com/products/acrobat/readstep.html. If that doesn't work, you might try using another computer.