Backyard Permaculture in a Temperate Region?

Hi!

I'm looking for resources on temperate permaculture. I like growing veggies and food in my yard, and have decided I want to step it up a bit. We have some small (baby) fruit trees (cherries, a nectarine, an apple), and I want to do more.

So I'm interested in permaculture, and want to find out how I can turn my yards into a low-maintenance food ... forest of sorts.

I need advice - species that work in my area/climate, especially legumes aside from beans and peas, and recommendation of plants to put in (with reasons).

A note - I want everything to either be edible or to support the edibles. Poisonous anything is not welcome - I have small children.

Any suggestions?