https://www.creativelive.com/For those who dont know this site - I have found it incredibly informative.
Live sessions with photographers/retouchers/designers/business ppl/ etc are done on a very regular basis.
All LIVE sessions (max 3 days long) are
free if you watch live streaming - or the re-runs.
There after you can purchase the courses and download it.
The editing ones was most useful to me - Dave Cross, Ben Willmore, Lesa and many many more.
I am a bit of a Photoshop Slut. (not that you could tell from my editing skills...!!! )
Purchasing these courses is a lot cheaper than attending workshops. Often they are on sale also.