Free Salesforce development book
At the Dreamforce conference they handed out copies of a newly published book called Creating On-Demand Applications with AppExchange. It’s a pretty nice capture of how you can do everything from customize the app via point-and-click, all teh way up through hard core programming. They even include a nice section explaining what APEX is and isn’t.
You can’t buy it on Amazon, but you can get a PDF for free from Salesforce with free registration.
