The current updates to this book include several recipe-style, step-by-step sections to quickly get things done. This is a go-to book for Alfresco development, but the current edition is old enough that some key things—like how to create an extension project—have changed significantly. A lot of this information comes from Jeff Potts’ Alfresco Development Tutorial series. He has done a great job of keeping this series up to date.
Another great new resource is the Alfresco community site. This is a Jive platform site that has all the old forum and wiki content, but also a lot of activity from the community. It’s a great place to ask development questions and get answers from true rockstars in the community.
Finally, we would be remiss if we didn’t mention that the developer documentation at Alfresco has improved drastically over the past year and a half. You may find some good info here.