Our new book is online, a chapter at a time. We have a dozen chapters in various stages of proofing and testing, and have the first 3 uploaded and available at http://arduinotronics.blogspot.com/p/citizen-science-book.html, so check them out, and leave us feedback on thoughts, problems, ideas, etc.
Posted chapters will be improved and added to and new chapters added, so keep coming back for more.