I'd like to learn the APA style guide, so that, in addition to the fiction and general non-fiction I work on currently, I can start accepting academic editing jobs. However, I know very little about the details of APA and I don't know what the best strategy is for learning it. I also understand it's very different from AP and Chicago, the style guides I use most and know the best.
The tutorials John linked to in the comments look like a good resource and, best of all, they're free. However, from experience, I learn best by hands-on, applied project-based learning. However, this style guide is a foreign country to me, and I don't know if my usual style of learning will work well with APA.
How do I learn APA quickly? Should I look for training right away, or, since I learn best when I have a project, should I dive right in and then fill in the gaps later on? At which point can I consider myself competent enough at the style manual that it would be ethical for me to start accepting editing jobs using APA? How will it be different from other, non-academic style manuals?