I don't use any fans on the tank. There is a 1" wide screen covered opening running full length of the tank at the back. Seems to work fine. Before I had the opening I had too much humidity and a small mushroom problem.
The humidifier I use is made by Holmes. It had a round vent on top that the fog came out of. I removed the vent and replaced it with a 2" PVC slip coupler. Then used differ fittings to reduce that down to a 1" piece of flex tubing. The tubing enters the top of the tank and hangs off the side by a U shaped piece of PVC. Much like you would use for a sump return on a fish tank. The humidifier sits below the tank. Sorry don't have any pictures, but, I might be able to find ones of simular units on some of the Frog forums I go on.