dons her "I wrote a free textbook and all I got was this t-shirt and a horrible case of burn-out" shirt Make sure you don't do what I did and get suckered into writing a course and then writing the textbook for the course over the span of a few semesters. Look around; there are certainly grants out there for developing open-access course materials that you might qualify for (or might get a faculty member to help you qualify for). All that said, free course materials are something I am always excited to see! Good luck, and if you want a second pair of eyes, just let me know.
That would be an ideal situation; hopefully it works out! Technically the copyright for my book is undetermined; the department paid to have me teach a course with the understanding that I'd write the book for it in the process, so maybe it is theirs, but also faculty usually own their course materials, so I have decided to just claim the copyright and if it ever becomes an issue we can argue about it then. It'd be foolish to argue copyright on a book that turns no profit anyway.