I build on-line books / manuals / tools my students use in the undergraduate courses I teach.  The e-books I have been working on over the past many years are best described as on-line laboratory manuals, which I affectionately refer to as OLMs.  I have built or am in the process of building three on-line laboratory manuals:  Cell Biology OLM, Histology OLM and Proteins OLM.  These manuals, each of which is at a very different stage of construction, are packaged in a suite I call the Biology OLS, a suite of on-line laboratory manuals for undergraduate biology.  Proteins OLM is the baby.  It is in a prenatal stage of development.  Cell Biology OLM is the most finished of the three.  It benefits from the 15 or more years I spent developing Histology OLM, the first of the three manuals.

For more, go to http://digitalscholars.org/courses/olms/ .