I don’t know about finding the free stuff; I always have trouble with that myself.
But here’s what I do when I make an ocean texture. I often use two plane objects, or two floor objects. One is a little bit lower than the first. On the top one I use a material with a bluish green color, and a bump channel with noise. The water shader works fairly well, but if you experiment with some of the other noise shaders you can get different results. It should also have transparency – play with the settings to figure out how transparent it should be. And reflection, and high specularity. The bottom floor or plane, has a material that is darker blue, no bump (not needed), no reflection, and can be a lot less transparent. Play with the Y position of the plane to get it so it looks right, but it probably shouldn’t be too far below the first. Using two objects this way can give a good sense of depth. For lighting, you can use the sun object, and also the sky shader.
Jack