Bacardi

You can indeed use Edit>Transform when the sky is on its layer.

If the images are still separate, you can open the one you want to change the sky of, note its width, then open the sky one and use Image>Image size and change the width with resample on so tha Photoshop recalculates the width.

gymmie

Welcome, SkyGuy!

Layers happen to be one of my favorite subjects You can do so much with them! And it sounds like you're off to a terrific start

To answer your question about "using black and white" to blend, that's most easily done by a layer mask. You can apply a gradient, use a brush, even use some filters on the mask...just make sure the mask thumbnail is active. When you click the mask icon (see image below) your colors should change to black & white automatically, unless you had a shade of grey for one of your colors. (Tip: to get the default b&w, type the letter "d")

The image below is certainly nothing fancy, but just something to show you a very small part of what you can do with layers. (It's a low-quality jpg to boot, but I wanted to keep file size down.) It started life as two layers, one black, one light grey. The circle on the right is the result of playing with blending modes, opacities, color fills, layer effects, and a layer mask.

Hi SkiGuy401 and welcome to the board! [righton]