Chocolata

One of my friends wants me to join her in writing a cookbook on foraged foods.

Sounds intriguing, but I know nothing about it.  And what really worries me, is all of the stuff I don't know that I don't know.  In other words, I have a feeling there are issues I haven't even thought about.  My friend grew up on a farm not far from here, and knows a bit about foraging - and has tried a few things, but she's not what I'd call "highly knowledgeable."

Anybody 'round here do much of it?  I'd appreciate whatever thoughts you care to toss my way.

I'm concerned about:
Legal issues
Could this lead to ecosystem damage, if harvesting a particular plant became popular in a given area?
Figuring out whether there are look-alikes for an edible plant (or other varieties) that may be poisonous
How far to go in warning people, like "if you're allergic to X, you're probably allergic to Y."
Probably lots of other things I haven't even thought about

Question:  I'm a decently competent cook, and I believe I can come up with appropriate, well-written recipes.  But do I have any business doing this, when I know little to nothing about the subject?

I'm trying to determine whether I would be getting in over my head, task-wise, and content wise.  I don't want people to get poisoned because we didn't warn them adequately, and I don't want to contribute to localized ecological problems.  

I'd be grateful for comments and advice.