Buy the O'Reilly book Designing Mobile Interfaces, or read it all right here for free.
Articles, slides and videos on the definitive, up-to-date, reseach-based guidelines on designing for fingers, touch and people.
A cheap, simple, plastic guide to help you keep the touch guidelines in mind during design and test.
Touch Overlays: Free stencils for use in your favorite wireframe or mockup tool, as long as it's INDD, AI, PSD, Graffle, VSD, or PPT.
Contact: With any comments, questions, corrections or to hire us for consulting or speaking.
Other devices: The patterns in Designing Mobile Interfaces are really best applied to small, portable devices. Here's some info and leads on other devices you may need to work on.
Writing: A list of all the articles I have written, as well as other books and research reports I have contributed to.
Speaking: Ask me to speak at your event, or see slides and videos of my previous talks.
Fingers, Touch & People
If there's anything I'm the expert on now, it's how people hold and touch their mobile phones and tablets. I'm trending towards fully writing a smallish book on it. I am working on it over hereabouts, but since it'll be a mess for a long while, just check out the Touch overview page for the most current complete articles, presentations, videos, guidelines and references.