Howdy Sean,
I thought I'd chime in with some recommendations I have found valuable. First, if you don't have it, Mollison's
Introduction to Permaculture has been informative and a good benchmark for me as is his larger more in-depth tome,
The Permaculture designer's manual. Personally when I think about gardens, I think annuals, however for food forests I think perennials, as a generalization. I also think Square foot
gardening has interesting techniques that are worth the time to read and explore. Finally, The new organic gardener by Coleman is a truly in-depth look at what it takes to grow annuals for for the market gardener. I include this book and think books like this are helpful because I believe they help build the skill sets one needs to proceed with the vast scope of Permaculture. Good Luck! and Have Fun!
Thomas Mitama farm