I've seen a technique where type and an image are combined together. I want to do a similar thing with some type and a photograph of water reflections. Where do I start?
Start by creating a new document that has three layers.
Top Layer - Water reflections image
Middle Layer - Type Layer (use a big, bold typeface)
Bottom Layer - Background.
Select the Water layer.
Choose Layer > Create Clipping Mask.
The water layer is combined with the type layer indicated by a small downward facing arrow and slight indent in the Layers palette.
Note: The preceding applies to PS CS and CS2 users. Earlier versions (PS 7 and before) used the command Layer > Group with Previous