"Welcome to our Free Photoshop CS Tutorial section! Here you will learn some stunning Photoshop image effects. Try out these effects and have fun learning them."
I was browsing around the other day looking for a photo of rain that I could use as a background, and I ran across this page, which showed me quickly how to simulate rain in Photoshop CS. While I don't use Photoshop (I use Corel), I was easily able to translate it to the functions my program has. When I realized it was just a page on a much larger website full of free tutorials I felt I had struck gold. They offer more than Photoshop tutorials too. Check it out, I highly recommend it.