These tutorials pick up after you've completed the sample "Hello World" tutorial. After you complete the tutorial on the WebOS site, you should have a basic understanding of how an application is created for the Palm Pre. Unfortunately, you're then abandoned to read about the technical specs of widgets and other things. That's quite the jump in knowledge!
So, I've created some tutorials to hopefully build on your newly acquired knowledge to expand the app you started at the WebOS site.
WebOSSchool (A very good "course" on WebOS development - Free Registration Required)
Flickr Nearby SDK Experiment (Short tutorial using the GPS)
Linux Magazine - Using Lists in WebOS (A good overview of creating lists)
WebOS Boston - Mojo Lists: Part 1 (Working with a static list)
WebOS Boston - Mojo Lists: Part 2 (Working with a list using cookies)
WebOS Boston - Mojo Lists: Part 3 (Restructuring the list code)
WebOS Boston - Mojo Lists: Part 4 (Working with a list using the Depot)
WebOS Boston - Basic WebOS Application and the Depot (A simple app that uses the Depot for storage)
WebOS Boston - Working with Cookies (Another demo showing how to store preferences in a cookie)
Creating your own medical apps for WebOS: Part 1, Part 2, Part 3 (This shows how to use Ares to create a basic medical app)
Develop your first game for Palm webOS with GMP game engine (Basic tutorial on JavaScript game development)
WebOS Internals (Great site for more than just development!)
Instructional for beginners (A PreCentral discussion/tutorial for those just starting)