My two bits of advice for learning Chef:

- Use chef-solo. (Edit: and use knife-solo to initially bootstrap Chef onto the machine.)

- Your first time, forget about cookbooks and just write a single site-cookbooks/myapp/recipes/default.rb. Use that to list packages, shell code, whatever.

This will get you started, and you can learn/improve from there.

Your second time, use librarian-chef, and as someone else said, freely clone cookbooks so you can adapt them to your needs.