Here is a list of YouTube reviewers that are very knowledgeable and are a wonderful source of information and skills. From Rebuilding to plain and simple product reviews the best review is an impartial one.
Phil Busardo
http://www.youtube.com/user/pbusardo
Rip Trippers
http://www.youtube.com/user/RiPTrippers
Grimm Green
http://www.youtube.com/user/GrimmGreen
Vaping with Twisted 420
http://www.youtube.com/user/VapingwithTwisted420
Igetcha69
http://www.youtube.com/user/igetcha69
Indoor Smokers
http://www.youtube.com/user/IndoorSmokers
The Jonny Vapour Show
http://www.youtube.com/user/TheJonnyVapourShow/feed
The Vaping Greek
http://www.youtube.com/channel/UCnWnGz5VVXme87MNUpm_Drg