Photoshop & Lightroom
Unmesh Dinda of PixImperfect is currently the best photoshop teacher on Youtube. His videos vary in length but his knowledge and teaching style make his videos very easy to follow his lessons. Each video covers a different tool or set of steps with not only very detailed instructions but detailed explanations of what is going on with each click of the mouse.
Photography and cameras
Perfect Picture School of Photography by Bryan Peterson.
Bryan has not uploaded videos for about 8 years but all the information contained within is just as relevant today as it was then. Bryan's videos are very short and snappy making them easy to remember. He has also written a few books of which I have a couple, they are very very good. Google Bryan Peterson.