Create a new file by going to File > New > Blank File ...

Use the following settings:

Create a new layer Layer > New > Layer ...

Choose blue as your foreground colour by selecting the Foreground Colour box

Choose the Rounded Rectangle Tool.  You will need to hold down the mouse

button over the shape tool to see the following menu:

Draw a rectangle for a button:

Create a new layer and take a moment to rename the layers that we now have:

Double click over the names of the layers and name the first one "button"

and the newest one "shadow":

Change the foreground colour to white.  Then choose the brush tool

Now shade in the bottom of the button until it is nearly white at the bottom.  It does not have to be perfect.  Use CTRL+Z to undo and try again.

Once you are happy with it go to Filter > Blur > Motion Blur

Drop the opacity of this layer down to 85%.  Press V on your keyboard

(to get the move tool) and press the up arrow on your keyboard 4 times. 

This will move the blur up slightly.

Now apply another filter.  Filter > Blur > Gaussian Blur with a setting of 5

You will need to shrink the height of the layer and move it up until it looks like this:

Move over this layer - right click the mouse and and duplicate it. 

Rename one of the layers "shadow" and the other "glow"

Select the glow layer and use the circle selection to rotate it 180 degrees ie

You will need to move them around so the glow is at the top and the shadow layer is at the bottom.  You may have to shrink the height of these layers to get it to look this the following:

Now select the shadow layer and invert it:  Filter > Adjustments > Invert

You will notice that there are grey parts that need removing.  Do to this select the eraser tool and very carefully delete them.  Use CTRL+Z if you delete too much.  You may wish to zoom in to make the job easier (CTRL and +). 

Once you delete the grey parts you should get something like this:

Now select the text tool and click on your button and type "Contact Us"

Highlight the text and change the colour to white.  You may wish to increase the size of the font to a size that is more suitable to the size of you button.

You should then save a copy of this and use it as a template for many buttons.

Optional:  How about adding a graphic?

Choose the Custom Shape tool.  You may have to hold the mouse button down over the shape tool that you currently have selected.

Select one of the graphics.  I have chosen the envelope

(you may have to get the computer to view all graphics first)

Choose a pale blue as the foreground colour and draw the shape on the button.  You may have to move the graphic and text into a better position.

And finally select the Rectangular Marquee Tool and

draw a box around the button.

Then crop it:   Image > Crop

Save your psd file and as a jpeg: