Donna,
The easiest way is to use special software for that purpose. It is rather tedious to do in Photoshop. You can always post-process the stitched panorama in Photoshop and sometimes it is helpful to pre-process the images to be stitched in Photoshop.
But the actual process of stitching the images is not really a Photoshop thing, at least not in the present version of Photoshop. I recommend you try the free demo of Image Assembler from Panavue:
<
http://www.panavue.com/index.htm>
The Panorama Factory is a shareware program with a free trial period, also worth a try:
<
http://www.panoramafactory.com/>
You can find out all about stitching software at PanoGuide:
<
http://www.panoguide.com/software/>
— Burton — (not associated with any vendor mentioned)