Deploying Rails Applications book by Ezra is finished and available
brainspl.at
brainspl.at
As for the book, I have the early beta and the beta that followed it. It's THE book on deployment. Ezra and boys at EngineYard really know what they're talking about.
If you're deploying a Rails app, this book is a must. It will save you hours and hours of wasted time.
Apache is an industry standard and there is no shortage of people who know how to deal with it. I like nginx, but neglecting Apache is a mistake: I find it much easier to talk to corporate drones if I mention that "Rails runs behind Apache". For many of them words like Ruby or Rails are already too much to swallow, why make matters worse by introducing yet another new kid on the block for no tangible reason.
Also there are hosting companies and your clients who may (and in most cases ARE) already running an Apache instance and have an admin who's in charge.
Basically what I am saying is that deploying on Apache is #1 thing to learn about deploying Rails, but it is by no means the only or even the best option.
Lightspeed is nice for smaller sites because the processes can go away when there is no traffic. But I'm not a fan of it much and it's not covered in the book.