The PHS SF424 application format and electronic submission through Grants.gov are now required for most NIH grant applications. Principles and fundamentals of good proposal writing are emphasized in this Workbook, together with tips and strategies that kept the authors continuously funded by NIH throughout their research careers. The Workbook is interactive in the sense that examples are provided after which the reader is asked to make a comparable response in his/her area of research interest. As such responses are made the first draft of the application evolves.