As one who has published a book used in college and tech-school classes ("Economics: Making Good Choices," Southwestern, ITP, 1996) I have some suggestions.

1. Write the book to please yourself. You can rewrite later to make editors happy.

2. College textbooks sales representatives can be very valuable resources. They know what is out there, what is selling, what publishers want.

3. An agent may help--but maybe not. I had a supposedly first rate agent who tried for a year to sell my book; he failed, even though he believed in the book and made substantial efforts to get editors to look at it.

4. Personal marketing is what worked for me. The editor who finally bought my book saw it because of the efforts of a sales rep who was a distant cousin of a former student of mine. The book nearly died three times, first when an editor got sick and died of cancer while the script was on her desk, and second when ITP bought Southwestern; then the acquiring ediotr (my chapmpion and mentor and sponsor and guy who wrote the advance check) moved on to another company.

5. When the book was first published there was no publicity, no advertising budget--so I took matters into my own hands and personally promoted the book at a big critical thinking conference. (A critical-thinking perspective is a distinctive feature of my book.) This promotion worked, and a woman whose family owns a chain of tech schools loved the book; they adopted it; many tens of thousands of copies were sold, and I got to retire early.

The most useful advice anybody can give to an author is:

Write the best book you can. Then hope that somebody likes it.

By the way, try to hold out for a goodly advance, because the bigger the author's advance the bigger will be the advertising budget.