Sure, this will be my 3rd published title (http://amazon.com/author/joelmartinez), though first as the sole author. From first contact with the publisher to today was about six months, actual writing time was approximately 3-4 months, and the rest of the time was the editing process (still have to review/approve the final laid-out PDF tonight, actually).
Process-wise, the first step is to have a solid outline and target audience in mind. That will inform the book's style and keep you on track as you put the proverbial pen to paper. When working on an individual chapter, I like to write most of it longhand. That forces me to rewrite it as I transcribe it to the computer and I find the end-result requires many fewer iterations to complete when I do that. Aside from all that, it's all the same things any author will deal with, things like writer's block, etc. Just make sure you are prepared to really focus on getting it done once you decide to write it ... because there's nothing worse than starting a project like this, and then letting it languish. It will always be on the back of your mind and you won't be able to enjoy relaxation time until you get back to it.
Anyways, hope that helped, happy to answer any other questions you might have :)
Congrats on the release. I just preordered a copy of your ebook. After writing articles on some networks, I've decided to start working on a monotouch ebook. Your tips of your process will come in handy.
On the side ... I work full time as a mobile application developer. Of course, I had to stop all other side-projects. I usually (against my better judgement) work on at least 2 other things on the side at any given moment, but this book took all of my extracurricular attention.