Just Enough Research
Just Enough Research is the latest book to come from the ever-excellent A Book Apart publishing group. Written by Mule co-founder Erika Hall, Just Enough Research delves into the nitty-gritty of doing excellent research for your projects, whether they be design-related or otherwise. Erika has been doing this kind of thing for many years, making her a foremost expert on the matter.
You can pick up a copy of Just Enough Research as an eBook for $9, a paperback for $18 + shipping, or both formats together for $23 + shipping. Before buying, you can check out a sample excerpt from Chapter 5, entitled Interviewing Humans.