OK, I guess this is somewhat of a rant. I still get this question so often off and on from friends, list members, students, I felt the need to write about it.
There is no official certification or license for you to become an herbalist in the USA!
There are many educational programs that may give you a "certificate of completion" all this means is that you completed a program from whatever school you attended. They may claim to be "accredited", what does that mean? Well it means if you have a another license, such as LMT, or Naturopath, you may be able to qualify for Continuing Ed credits (CEU's), and that the school has met certain standards by whatever accrediting agency it belongs to, this does not mean the credits transfer to any college for credit hours!! If you think that going to a school that is accredited equals a better education, this is not necessarily true.
Someone said "But I want to have an accredited education so I will be respected in the allopathic world"
Hate to tell you, but most Doctors either are warmed up to the idea of herbal medicine or they are not. Saying you have a certificate from so and so school that you paid a pretty penny for really will not sway them, because for the most part they have no idea about these schools and have little time to listen to what you have to say. Some Doctors think that Chiropractors are quacks, and they have a DO degree, spend tons of $$$ and time on their education. The "licensed" practitioners clash in the medical world all the time.
I have said this before and I will say it again, some of the best herbalists I know are self taught. They do not hold a certificate from one of the major "accredited" schools. Most of the pioneers in herbalism, Juliette Levy, Rosemary Gladstar ,Susun Weed, for example paved their own road- learned from the people & the plants, they did not need a certificate to start learning. A few in my generation (and 2 of my favorite) are jim mcdonald (read his bio here) & kiva rose (she explains what she does well here) ......and many others.
There are tons of resources and it can be very overwhelming. Starting with one of the many programs will give you a good foundation, but you will find this is a lifetime passion, and you will learn new things daily, you may later decide to expand your education, or focus on your own niche. I still have classes I want to take, books I want to read, plants I want to meet. I think if you have the opportunity to learn from the herbalists themselves this is a great start. Research the herbalist you are going to work with, do you like their teaching style & the type of herbalism they practice? this can make a big difference in what you retain and learn. Join some of the online forums like herbwifery, Susun Weed ,take hands on classes in your local area, read books ( I think The Herbalist's Way by Nancy and Michael Phillips gives an excellent overview of what an herbalist does, profiles different herbalists and their teaching styles, talks about different events and programs, even teaches you a few things to get started as a community herbalist yourself!- if you can buy it directly from them, they are such nice people!) join herbal email lists like medicinal herb list, the herbstudent yahoo group, medicine woman mom's, tribe, go to Henriette's site, she has tons of free information that will keep you busy for days, visit jim mcdonald's article index for other great resources, and of course visit all of the wonderful blogs (check out my links on the side bar). A great new website Herb Mentor launching March 20 2008.
Before you jump into a major program and spend tons of your hard earned cash, I would really do some soul searching and research the both the instructor and the style of herbalism they practice, start with immersing yourself with recourses, books, websites, et ask around how did others like the class? Make some teas, get out in nature, practice at your level of experience, then the right instructor and class will become apparent to you.