McNeel provide an excellent and comprehensive collection of tutorials and learning resources for anyone unfamiliar with Rhino or 3d modelling. These can be found here:
If you are a university student or faculty member your institution may have a subscription to Lynda, an online learning platform with tutorial videos for most industry standard modelling packages. The Rhino tutorial videos are here:
Rhino User Guide
A collection of tutorials and guides are also published in the Rhino 5 (or 6) online user guide. These can be accessed here:
While actually using Rhino, it is useful to have the Command Help window open at all times for animated instructions, tips, parameters and related commands. Many of Rhino's commands are intuitive (type Box to make a box etc) and a great way to learn can be to dig around in the menu's to find a tool that sounds like what you want.