What really made me start digging into this world of WebApps was that I wanted to start developing for iOS, so I bought a book about iOS development from Pragmatic Programmers called iPhone SDK Development. Which is a great book, but after some chapters I was getting nuts because of Objective-C, it's a very very very strange and antique language that has a lot of stuff that isn't so good for this modern days, but for historic reasons Apple use it as default language for everything.
So as you can see this first Recommendation entry will be about what made me dive deep inside this and learn a lot. This screencast called HTML5 Mobile Web Development, from O'Reilly and CreativeLabs costs $139, but it's worth every cent if you really want to learn building very useful apps and with real-world examples. The classes are very good and you learn a lot.
On this course Jake Carter will teach you how to build a simple Twitter client with Home, Mentions, Search and geolocation, handle device rotation, local data storage(databases), build a Contacts app and a lot more. So you will learn by making real applications as you can see, which makes the course a lot more interesting, instead of just trowing information and hope you learn, he teaches by using real-world examples.