Well, I am quite compatible with photoshop and I personally think that I could make myself an e-book on many techniques used to make templates and/or logos. I think that there are a lot of designers here and I think I could sell quite a few if I sold it for like $10.00 a copy or something. Do you think that there is enough buyers?
If it is good I would definitely be interested (at that price)...Especially if you offer resale rights. PM me if you decide to make it.
Remember, there are buyers everywhere - not just on DP. Write a decent product and then put all of your energy into marketing your book. It should sell well if the work in sound and you promote it to the right groups.
I think a better option might be to make a PS tutorial site and then offer a book with some additional tip/ tutorials that they get only from buying the book. This way you can establish some sort of credibility in the field, because believe me, there are some rubbish tutorials out there. You would also have a site that could generate additional revenue on possibly a longer term basis. just my 2 cents...