VIEW and make sure Snap to Guides is checked.
Note: You can make just about anything for a navigator in Photoshop and then use this way to cut it up to put on your site.

Click and hold down the mouse button on the ruler and drag out a guide line. Its ok to let go, you can move the guide any time by clicking on it again. Keep repeating this step until you have all your little buttons in their own cells.

Last select the Rectangular Marquee tool and select your buttons, use the guides for a path. Now go to Edit>Copy Merged to copy the button into memory. Open a new image and Paste it in. Now save it. Continue till you have them all saved, then import them into your HTML page and put it all together.