Starting  Launch PhotoShop.  Go to File--New Put in the size of your button and choose RGB Color in Mode.

 

Color Button This gives you a blank canvas on which to work.  Choose a color for your button in the Foreground Color menu.  Click the box in the upper left.  Slide the color scale on the right to the approximate color you desire.  You can refine that color in the box to the left by moving the circle.  Choose the Paint Bucket tool in the Fill tool menu.  Click in the canvas to add that color.

 

Adding Effects Choose an effect from the layer toolbar.  You may want to try some different ones.  You can always undo from the edit menu.

Adding Text

Choose the Text tool.  Click in the button.  Set the font, size and color.  (You can change any of those by highlighting the text making the changes from the text toolbar.  Click OK.  Move the text by selecting the Move Tool and dragging the text.

Add text effects the same way you added the effects to the button.
 
 

Edit your work To change your colors or styles, you must select the layer from the layers menu on the right. Double click on the name of the button to edit the font text, color or style. (This is how you can make several buttons with the same background.  After you Export as gif double click the button text from the Layers menu and change the text and Export again with a different file name.

 

Saving To save your button as a GIF or JPEG file, go to File--Save As.  Choose your format and save the file.   Another option for saving web graphics is to select Save for Web from the file menu.  This will allow you to optimize the graphic for web use.