Jim,

I suggest you check out my training books. The "Glider Pilots
Handbook of Aeronautical Knowledge" covers everything you need to pass
the written test. A companion workbook is available that includes
every question that is on the written test, as well as many others.
If you can answer all the questions in the workbook, and can pass the
online practice test at www.exams4pilots.org you should have no
trouble passing the written test. You can present your completed
workbook and a printout of a practice test as evidence to your
instructor that you have completed a "home self-study" course, which
should be sufficient to get the sign off.

If you would like to see excerpts from the book, you can go to the
website www.gliderbooks.com.

Hope this helps.

Russell