Well I use layers to do it all
1st I took the tower used the poly laso tool to cut out the sky
added in the sky from a nother shot and cleaned it up some used the cont. tool for the darken
As for photoshop class i take one at columbus state here in columbus it was about a 150.00 class and you can get it at just about any school in your town. But I will say the only thing we talked about the 1st day was the laso tool and how layers work the rest of it i did on my own just playing around last night using photoshop 7.0