Saving your texture - Important ! [Comment]
It seems those videos don't explain properly how to save your texture. I have spent like 3 hours painting, saving in both the UV editor and the blender file itself - only to find out, after opening - that it had all gone to waste. I suggest to incorporate the "Saving of Textures" routine into the videos. Anyway, there are a few ways to do it correctly - here is what worked for me:
1) In the UV/Image editor - Create a new Image / UV.
2) Unwrap your model in the 3d view and look for the UVs in the editor.
3) If you do 3d painting like myself- start to draw. Draw a little just to see if the save procedure works for you (it should).
4) In the "UV Editor", save to disk using menu "Image" -> "Save as Image" if you haven't done so already. That will save the initial file to disk.
5) Continue painting a little more.
6) You are now in the 3d view with "Texture Paint" mode. Hit "T" if the "Painting properties" section is hidden (while cursor in the "3d viewport"). A menu will appear on your left.
<So now how to actually save >
5) Choose "Slots" tab and choose your UV file from the dropdown under "Canvas Image" (if it's not already there).
6) Once you picked it - hit "Save All Images" button. When you do that - in the UV editor the Asterisk ( * ) will disappear.
THAT IS NOT ENOUGH.
7) Now, save your .blend file (new or override existing - doesn't matter). You are now safe to go :)
This was learned the hard way...
Good luck on your journey to greatness.