Zero to Superhero: http://zerotosuperhero.com took me four and a half years to research, write then format and self-publish, so I know how much work it can be.

Then again, my second book Economtricks: http://www.lulu.com/product/paperback/economtricks/6123536 took only a year and a half, and every aspect of it went smoothly.

So maybe there's something to be said about having gone through the process once, it gets easier.