Landscape Book

[Bob Wonderly]

I want to create a short math book that incorporates mostly large PDF 
graphs (generated by gnuplot). These graphs need to be displayed 
landscape. There will be some explanatory text and equations. How can I 
make the whole book landscape format?

Thus far my attempts are only displaying part of the graphs and the text 
is still portrait.

I looked at the FAQ's and did specify "\usepackage{lscape}".