One way to market your ebook while also getting a link back from a high ranking site is to create a lens on Squidoo. This site was created by Seth Godin as a way for people to focus on one particular aspect of what they do. Your lens is intended to be on one product, service, or idea, but you are free to do what you want.
Squidoo will only take you about fifteen minutes to set up, and since it has a Google page rank of 7 and is rated by Alexa at less than 1,000, the link is definitely worth your time. You can add more information as you get further along with the writing of your ebook, and when it is finished you can also create a lens to sell your ebook.