Form Design Patterns
by Design: Interaction Design to Lead Us into Temptation by Chris Nodder that explains how an understanding of human frailties can guide your design decisions. Each chapter deals with one of the Seven Deadly Sins (Gluttony, Pride, Sloth, and so on).
Steve Krug • Don't Make Me Think, Revisited: A Common Sense Approach to Web Usability (Voices That Matter)
Caroline Jarrett has an entire chapter about it (“Making Questions Easy to Answer”) in her book Forms that Work: Designing Web Forms for Usability.
Steve Krug • Don't Make Me Think, Revisited: A Common Sense Approach to Web Usability (Voices That Matter)
generally advisable to keep your input forms as short as possible.