my recommendation to those that already have a foundation in some permaculture happenings....
see if there is a permaculture guild in your area...integrating permaculture into your life as its already established
Intern at a PC farm....recommendations (mostly on the west coast since it is what I'm most familiar with):

www.oaec.org Occidental Arts and Ecology center

www.permacultureportal.com/Hm.htm Bullock Brothers

www.regenerativedesign.org/ Regenerative Design and Natural Awarness

www.newcollege.edu New College for an accredited version

www.permaculture.net/courses...ngs.html permaculture net web base

www.organicvolunteers.com/ YEAH...Organic Volunteers!!!! self direct your long term course.

www3.telus.net/permaculture/...I've always been curious about them...and in B.C.

Those are the top choices....
good luck...I know there are many more.
@

okay i'll throw in some words since these sisters hav given such wonderful gifts to the string, ahhh we are all so beautiful...but i'm inspired so here,

yes living routes, i did the program in auroville three years ago; living routes offers semester long courses that are based in a variety of evolving consciousnesness and earthened sustainability terrain...last i knew, they had programs in auroville, scotland, brazil, western mass, senegal, mexico and oh i just checked the website (www.livingroutes.org) and they now have a program in peru...if u are interested in the auroville (india program) lemme know and i'll share stories and contacts with you...i also have several friends who went to findhorn (scotland) with living routes and also a friend who went to brazil, and i can get u in touch with them...*highly* recommended...beautiful...

also auroville itself as a community, and smaller groups in the community, has various educational programs, they have some amazing work happening there, and i sugest at least checking out the website for internship opportunities and the winter integral studies program...solitude farm is a wonderful place that i interned there and u can go and wwoof there and will learn deeply faithfull and skilled techniques...they grow much of their own food fukuoka style ("one straw revolution") and live really simply, and necessarily incorporate permaculture lifeways in there...a lot of whats hapening in auroville is permie style...

i totally support pepita's suggestion of the global ecovillage network, gen.ecovillage.org/, tons of website links there to peruse and see if theyve got educational programs and internships, etc

i have a friend who *LOVED* the collaborative eco-lifeways program that spans between finca ipe and punta mona in costa rica, www.fincaipe.com/internships.html...

earthaven, www.earthaven.org/, in north carolina has awesome internship opportunities, mostly that begin in the spring...and theyve got sweet educational opportunities...

aprovecho sustainability education and research center near eugene, oregon is like a second home for me, and u can do an internship for three months there where u'll learn hella and/or u can worktrade there and learn hella...u are welcome to stay for as long as u choose to, it's a very resourcefull setting in many ways...www.aprovecho.net...

i did the ecovillage and permaculture design certification course at lost valley as pepita referenced above, www.lostvalley.org...lost valley is a wonderful concentration of energies and i met some amazing beautiful beings there, and the teachers have a lotta wonderful info and u can get connected to the local permaculture community in eugene which is soooo stunningly starlit...i'm so impressed by them...losat valley also offers long term permaculture/land steward internships....

in eugene, oregon itself there are so many activated peoples who are interested in sharing sills, knowledge, wisdom with other for sure...just get linked up with the permie guild there, and yeah like aurora said, there may even be a permie guild where u're at, that's a wonderful resource...but if u're interested in seeing urban permaculture work in action, there's an urban ecovillage in eugene called maitreya ecovillage (i have two heart connectio friends there if u want contacts), and there's tons of people enacting awesome earthened work, dharmalaya is a beautiful spiritual center/permaculture center that u can wwoof at there, i also have some contacts to people who live ther who are permie wizards and wizardesses and can get u connected if u wanna share their settings or just live in eugene and work with them...the peoples in eugene are planning a major regional permaculture gathering to be held in the same grounds as the oregon country fair, so that gathering will be a wonderful space to meet opportunities...

portland is highly activated in urban permie work as well...did aurora mention city repair, www.cityrepair.org/wiki.php/about, or the try/on life community farm, www.tryonfarm.org/...

there are also permaculture-oriented communities and education centers around the country that offer work trade opportunities where i'm sure u'd learn hella, and can stay for long term positions...totally suggest www.organicvolunteers.com, amazing database...

oh and there's a place in british columbia whose program i admire, place called o.u.r. ecovillage, www.ourecovillage.org/...

and there's a place caled ecoversity in santa fe new mexico that has full year-long in-residence training...it looks cool...i have a friend who teachers there occasionally and she seems to love the place...www.ecoversity.org/index.ph...index/...

so yeah, here is a bitta spill from my brain...probly more in there awaiting a lil shaky shake out, but hope this feels helpfulllll, and be in touch if u have any questions, further interests, etc, i lovvve to offer all this stored knwoledge to others as often as possible...

(i also have a couple friends around the country including alaska who are doin permie-style startups on pretty newly aquired land, so if u're wantin to help in those types of fresh efforts, lemme know, i can try to help direct u to a home...)

there's good stuffs occurin everywhere, much aloha, love n blesssssS

*k~straw~ma*