There are a lot of different plants growing everywhere, and the best thing about it is that many of the common ones can be fairly useful. I don't have any formal knowledge in ethnobotany, and you should, of course, cross reference and be cautious in what you try (just think about how many different crazy allergies people have to domestic plants - wild plants aren't going to be any better about that.) But enough warnings. Hopefully you'll find this information useful and work up the courage to use some of the "weeds" growing around you.