Let me address your questions:
Is Ajax the best thing since sliced bread? No, not at all. Ajax is just an ends to a means. To get the full benefit of Ajax you need to combine it with a good server side strategy and my thinking is REST. Many people think Ajax is all client side, or all server side. I say it is both, but a de-coupled both.
What Ajax brings to the table is the ability to de-couple the client from the server. Think of it as follows. When we develop
Java components we use interfaces, implementations and factories. Yet for the Web we like to hard code everything with URL's that reference specific HTML pages. With REST you have the ability to define a resource (aka interface) and its representation (aka implementation).
Personally, my favorites for developing Ajax applications are the patterns in my book (
http://www.devspace.com:8088), Prototype, and DojoToolkit. On the server side I feel what we have is enough. I feel many of the server side frameworks lock us into specific ways of doing things. To compare it, imagine writing a
JBoss application that when executed on the client side required a JBoss client API. We would never accept that!
With respect to book references; My book, Danny Goodman's authored books. I also advise getting a very good
IDE that can code HTML! I personally use Komodo, and Visual Studio (the HTML, CSS stuff is pretty good). X-Develop which I use to code Java, and .NET will be releasing a more comprehensive Ajax development environment, but that is still a few months away.
Now with respect to your plain vanilla database application. I would combine the Content Chunking pattern with the REST Based Model View Controller pattern. However, what's your time frame? Could you wait a month? I am right now authoring Ajax Recipes and would like to add this as a recipe since it is a common question. Send me an email and we can talk further?