@umbra21 - It does worry me though that a lot of people know a little bit about herbs but very few people know a lot. Sage tea, for example, can be very effective, but it can also mask a fever that might otherwise show someone they need to go to a doctor.
Certain types of herbs should never be taken by pregnant women, or by children, or need to be taken in fairly precise amounts.
If you want to do anything more than just use herbs in your food, I would take a real herbalist course and learn all the dangers.
On top of that, you also need to know how to pick and prepare the herbs properly. Remember that leaves will have different strengths depending on where you pick them, how late in the year it is, the time of day and so forth.
It's complex and not something that I think people should dabble in.