There are two good methods I can advise on. First way is to use plain text (easiest) and the sceond way is to make a custom brush and apply that.
The advantage of using text is that its relatively quick once set up and it can be changed easily and quickly. The advantage of applying a custom brush is that you can use images as well but once its made you need to make a new one if you want to change it.
Here we're going to use the text method...
Load up a photo that you want to apply a watermark to and select the "text" tool. Now add your copyright text, not forgetting that if you hold down ALT and key in 0169 on the numeric keypad you can obtain a copyright symbol. For the best effect I've found using black text works most effectively.
Now, right-click on the text layer and select "Blending Options" to open a small window. Select "Outer Glow" and apply the following settings then click "OK":
http://www.pictureinthesky.net/exter...ingoptions.gif
The reason for the white outline is so that if your watermark falls on dark areas it'll still be visible. You can, of course, tweak any of the settings to suit. If your copyright text is quite small you might want to reduce the size of the outline by changing the "size" setting.
If you want you can rotate your text so that it takes up more space than a small rectangle. From the "Edit" menu select "Transform" then "Rotate"and a box with eight handles will appear around your text. Using one of the corner handles, drag one of them until the text is at an angle you're happy with. A setting of -45 degrees is what I use. Once you're happy press the return/enter key on the keyboard to apply it. If you don't want to rotate it just press escape (Esc).
Your picture will look something like this:
http://www.pictureinthesky.net/exter...ghtexample.jpg
Now all that's needed is to change the opacity of the layer until you're happy with it, a value of between 6-10% I find is adequate. This is what I've settled on:
http://www.pictureinthesky.net/exter...dwatermark.jpg
Apart from saving your finished picture out all that's needed is to save your watermark so you can use it again. To do this we need to save the file out again but this time as a Photoshop (PSD) file. Now when you want to apply the watermark to other pictures all you do is load your watermark PSD file and then load another picture so you have two project files in Photoshop. Using the Move Tool (V) make sure the text layer is selected in your watermark file and drag the layer from the picture into your second picture. This will copy only the text layer into the other picture.
You might want to play with the size of the text, change it or rotate it - it's entirely up to you.