With 4 steps, you can read PDF files on your iPod. To do so:
1. Open the PDF document in Adobe Reader and save it as a text file.
2. Upload the text file to either eBookhood.com (my first choice) or iPod Notes Packager to convert it to Notes format, then download the converted file (i.e., zip format).
3. Plugin your iPod and make sure Enable Disk Use is enabled in iTunes.
4. Extract the zip file and place it in the Notes folder.
Viola! Simply navigate to Extras > Notes on your iPod. The whole book will be automatically linked for iPod reading.
This should get you started on reading more.