This book titled "Theory and Practice of Online Learning" is a collection of chapters written by various staff at Athabasca University in Canada.

I have just downloaded it (about 2 meg) and looked at the table of contents. It look promising. It comes out at 454 pages in Acrobat Reader. The book is published under the Creative Commons licence and can be downloaded for free in pfd format. It is also available in hardcopy for $50 plus shipping (presumably this is Canadian dollars).