First of all create a new document with white background color.
Choose your letter for converting to the 3D logo. I’ve chosen “N” for this tutorial, but feel free to use each letter you like, it works!
Now click on Horizontal Type Tool , choose a font and type your letter

In the Layers panel, right click on the letter layer and click on Rasterize Type.

Now, we want to transform its shape and make it something that looks 3D. For that, go to Edit > Transform > Skew and make the top points a bit closer.
Also, as you see in the image below, you should change the bottom of the letter as wel

My transformed letter

We’re going to extrude the letter. Well, make a copy of the letter layer (duplicate it) and press CTRL + G to move it into a group.

While the copied layer is selected (”N copy”), Hold Alt key down and hit the down arrow key about 20 times.
Here’s an image of Layers panel.

OK, now click on “Group 1″ in the Layers panel and press CTRL + E to merge the group.
You should have two layers after merging the layers of the group.
Your result should be something like this:

Select the merged group layer and double click on it in order to open Layer Style dialog box.
Select Gradient Overlay and apply settings below.
I’ve used green for my logo.

Result

Now click on OK button and open the layer style dialog box again, this time for the first layer.
Apply following settings.

After adding the style
Final Result:

Via : 3D Text Style