There is a lot of talk about this in a lot of threads, but I cant find a how-to in the user manual or online help guide.

What I have done is to create a plane, go to the shader room, and make Top Shader -? Flat Mapping, then a Texture Map and chose a PNG of a tree.  That made the tree appear on the plane, but the tranparency did not work quite right (a lot of white in there) and the test render showed nothing, just a blackness.

I also tried a multichannel, with texture, and an alha channel...nope

I also tried a JPG with white, and clicking white is invsible, and nope again. 

I have not gotten anything to show up in a render or test render.  Mixed results in how it shows in the textured preview.

Is there a quick how-to on this?

(once I get this, the next steps are face the camera and produce a shadow...but I will experiment a little to see if I can figure those out)