1. Welcome to RubyMotion
This is a great introduction to RubyMotion and a great way to get your feet wet.
2. RubyMotion Tutorial
by Clay Allsopp
A dead simple introduction to RubyMotion that walks you through the steps of getting started with your first app.
3. Motioncasts.tv
by Hendrick Swanepoel and Michael Erasmus
Motioncasts is a paid series of screencasts and tutorials that walks you through some of the basic elements of RubyMotion and then progresses into more complicated pieces like Weak References and Autolayout.
4. RubyMotion - iOS Development with Ruby
by Clay Allsopp
THE book on RubyMotion written by Clay Allsopp and published by the Pragmatic Programmers. You have to own this book if you are getting started with RubyMotion!
5. @RubyMotion
The RubyMotion twitter feed is a great way to find new blog posts and projects. The account is very active and tweets very frequently.
6. RubyMotion techniques: A few nuggets
by Steve Ross
A great post to read if you are new to RubyMotion and/or iOS development. Covers some very good basics to know as well as some not so obvious gotchas. At the moment this is a blog dedicated to RubyMotion, Steve has got some great content going I hope he keeps it up.
These are the resources I have found useful to me so far or have been told (the book) are. Please tweet your suggestions to me at @gertig or leave them in the comments.