Video Tutorials are definitely a great thing and very interactive indeed. But I stumbled upon a site; which has no Video Tutorials but yet by far the best Tutorial Site for Smart Phones and Tablets that I have ever come across
They have tutorials across all well known brands; Alcatel / Apple / AudioVox / Blackberry / Ericssion / HTC / Huawei / Kyocera / LG / Motorola / Netgear / Nokia / Novatel / Pagers / Palm / Samsung / Sanyo / Sierra Wireless / Sonim / Sony and more
Below are links to a few popular ones
Tutorial for Samsung Galaxy S5
Tutorial for Samsung Galaxy S4