Plot.ly tutorials?

Hi,

Are there any good references or good tutorials for plotly. I am especially looking for tutorials for 3D graphs.

I have been googling for hours and I cannot find anything, About 10 times I ended up on the plotly description:

Unfortunately this is not detailed enough for me. I just need to find out how you can plot 3D graphs for multivariate functions and I also need to know how you can plot good old planes.

Hope someone here can help me out!