This is one of my favorite text effects, in the end you will have letters like the one below

First off make some text, make sure that it is large and bold like the image below.

Now take your text tool and right click and choose rasterize type

Hold Ctrl and click on your text layer on your layer pallet to select an outline of your text

Now take out your gradient tool, making your forground a light grey and your background a darker gray fill your selection so that your text looks like the image below.

Now go to edit> stroke and use the settings below

No go to Select> Modify > Contract and use the settings below

Now change your bg and forground from your light grey and dark grey to a light and dark green. Now fill your selecting with the gradient once again, this time with the darker green towards the top.

Now go to edit, stroke and use the settings below

Now we are going to make a new layer. Go to layer> New layer and take out your gradient tool once again. This time set your forground color to white and from the drop down menu at the top of the screen choose the gradient type circle in the image below

Now use your gradient tool to fill your selection about half way. Next take out your circle tool and delete the bottom half by selecting the opposite of what you want deleted and choose Select> Inverse

Now just add a drop shadow and you are done!

When you are finished you image should look very similar to the one below. If not you might want to try it with a different text type.