David Brinnen and Horo
When it comes to learning Bryce, these are two names come to mind without a second thought.
Many of the Bryce products at Daz 3d are made by them, and they've also always been incredibly generous when it comes to helping the community to learn Bryce.
They have a really nice Tutorials site: bryce-tutorials.info, which is loaded with resources
and there's also David Brinnen's immense YouTube channel, full of in-depth videos and Horo's cool website: Horo.ch
For Horo's site, head to the category you'd like to explore, then use the text on the main page as a guide, and make your selection from the links on the left ;)
When I saw this video by Horo I got really jazzed about installing Bryce and getting to know how to use it.
I do a lot of this sort of thing in Carrara. That's how I like to get interesting terrain for my wilderness scenes.
Bryce is a totally different beast than Carrara, yet I still feel compelled to take a little time to get to know it!
This 20 minute primer, by David Brinnen is a really nice look at how to get started.
It's a video like this that helps me relax about getting started.
It'll help me to cut a lot of the entry-level learning curve down - just knowing a few simple secrets to get going.