Ladies and Gentlemen - introducing: Frederik Steinmetz! He has prepared an intermediate tutorial on Cycles. Not the usual "How to start Cycles and set up a simple scene" kind of tutorial but a guided tour around current pitfalls and lots of tips and tricks!

It's fairly easy to dissolve objects in Blender, but you can go even further. Learn how to use particles, a point density texture for volume rendering and a moving force field to get a ghost-like effect.