First, a Web service that "meets an unmet need." Back in 2005 I built a "code snippets" site using the then-nascent Rails in just over 24 hours. I then spent a second day making the design more "Web 2.0" a few months later, but otherwise did little except mention it here and there and add my own code into it. It made ~$800 a month from Adsense for a couple of years and then I sold it to DZone for $30,000. Perhaps the…
How many pages do you need for an e-book typically?
Its really not quantity! This is a market of quality. Just look through clickbank's affiliates for ideas for crap landing pages and crap ebooks (for the most part, spare maybe ~10).
Good sample pages, good outline, no boring plain black and white text, and connect with what your clients really need. Create a wiki/forum or something for registered users to access. The book isn't the only part... you want to build a community (elo adsense!)