The ever-helpful MDN provides a concise and complete guide to the new input types at https://developer.mozilla.org/en-US/docs/HTML/Element/Input/. PPK has detailed tables showing support on the desktop at http://www.quirksmode.org/html5/inputs.html and for mobile devices at http://www.quirksmode.org/html5/inputs_mobile.html.
Ryan Seddon wrote a polyfill for providing HTML5 form capabilities to browsers that don’t support them natively: Find it at https://github.com/ryanseddon/H5F/.
Bruce Lawson’s discussion of autofocus accessibility, “The Accessibility of HTML 5 Autofocus,” is on his blog at http://www.brucelawson.co.uk/2009/the-accessibility-of-html-5-autofocus/.
HTML5 Rocks has a good overview of the Constraint Validation API at http://www.html5rocks.com/en/tutorials/forms/constraintvalidation/.
A useful application for testing regular expressions is Rubular. Don’t worry that it’s aimed at Ruby; it works just as well for JavaScript and HTML5 forms: http://rubular.com/.
And your humble author wrote an introduction to CSS3 pseudo-classes for HTML5 forms at HTML5 Doctor: http://html5doctor.com/css3-pseudo-classes-and-html5-forms/.