Start with the tutorial on this link. They are simple, well explained and therefore easy to follow. They use CS6 but 3D in Photoshop has changed very little since CS6 (CS5 looked quite different)
Which takes you to this lovely front end. Isn't it pretty?
Five minutes later, you bang your head against the wall, because there is no search facility, and no clear way to proceed.
You could click on Most Viewed or one of the other tabs, on the off chance that most people watch 3D tutorials etc. I have been complaining about the Adobe TV front end for years. It used to be less pretty, but waaaaay easier to navigate and find stuff. So probably best to go with Option 1.