Cheaper here:
http://www.amazon.com/PhoneGap-Beginners-Guide-ebook/dp/B005OYJUKI/ref=sr_1_2?ie=UTF8&qid=1329088517&sr=8-2Don't see anything free either, though. Reviews complain about the book, unfortunately, so it might not be what you need it to be?
You can use typical AJAX to get an external page (jQuery or roll your own), and you can also determine the online status of the phone. I can go into more detail, but ultimately knowing what kind of app you are trying to build is going to help give examples that more match your needs.
If you want, view my github repository (
https://github.com/photokandyStudios/GreekInterlinearBible) for the app I'm currently building. Requires latest version of XCode and at least iOS 5 to run, but perhaps some of the code would be of use? Pay attention to the README.md file -- it describes the portions that are under CC-BY-SA/MIT license and what isn't.
Also keep in mind that the app is under development -- not released yet. No guarantees what-so-ever that Apple will accept it or that it will work without bugs, etc. But it's what I'm working with ATM, and is the best example I personally can provide of a complex app using phoneGap. I'm sure there are others that have even better code, and perhaps they will share with you as well.