My approach to permaculture is following a formula that has worked well for me in grasping new technologies in the software world: learning with incomplete understanding.
A large part of learning anything new is absorbing the vocabulary that its adherents communicate in - both the new words and more importantly the new meanings of old words. For example, my current day job overloads the word "transaction" to have 4 distinct meanings that everyone is expected to instantly understand from context.
Permaculture is no different: mono culture vs poly culture, nitrogen fixing, stacking functions, ethics as opposed to principles, humus (apparently pronounced "hue-mass"), vermiculture, C-N ratio, NPK, and on and on! Then add in the people: Mollison and Holmgren, Holzer and Fukuoka, Bell and Hemenway, Jacke and Salatin - they become a shorthand for the things they've pioneered. Finally there are the plants, fungi and animals, whew!
So I sip from the firehose at first - rushing through the books. If something doesn't make sense at the moment, then I just bull ahead until I get to something else, trusting that eventually it will connect with the rest of the vocabulary web that I'm building.
I'm not really absorbing these first several books. They are adding to my framework, but I'll have to re-read them and probably a couple times. The best I hope for at this point is that I can remember where I saw that discussion of weeds as pioneer plants...
Too soon to say it is gel-ing for me yet, but going through the Omnivore's Dilemma was the first glimmer of it - reacting to the content and being able to think about it in a context.
Still, the long lists of plants and their attributes are only getting a quick glance - I'll sweat those details when they become more relevant.