We love working with paper forms, but were persuaded that it was better to write a short book - so we concentrated on web forms. Most of the chapters work just as well for paper forms design:
Introduction: what is a form - works for paper
1. Persuading people to answer - works for paper.
2. Asking for the right information - definitely works for paper, and some of the things we recommend such as watching people deal with the incoming forms are a lot easier to do with paper
3. Making questions easy to answer - definitely works for paper
4. Writing instructions - definitely works for paper
5. Choosing forms controls - focuses solely on web form controls, so it's not really relevant for paper
6. Making the form flow easily - the parts about validations are only relevant to electronic forms. The bits about breaking a form up into topics are relevant to paper
7. Taking care of the details - works for paper, although obviously on paper you can't enforce required field indicators so just leave them off.
8. Making the form look easy - the sections on grids and grouping are relevant
9. Testing - definitely works for paper.
Articles on paper forms
Two of Caroline's articles are about paper forms:
"Designing usable forms: the three-layer model of the form"
"Understanding the costs of data capture"