Sorry I took so long to get back with you- great job!
I have a place in southern Illinois that I need to take a similar type of photo- if I get around to shooting the photos, I might have to ask you how yuo did put them together (I have a Canon digital Rebel, so maybe I already have the software?)
The camera itself has a Stitch Assist mode, which is shown on the selector on top of the camera as two overlapping rectangles. With this mode selected, you take a shot, and that shot stays in the left portion of the viewfinder, with the "live" view appearing to the right. You can then pan right to line up the previous and "live" images, and take the next shot.
Without the above in-camera feature, you can still use a tripod or hold the camera more or less level and take your series of shots.
The software is "ZoomBrowser EX," and there's an Edit button. When you click Edit, "Stitch Photos" is one of the options. If you were able to take the pictures as above, they appear as image files whose names start with "STA_" and you can follow the prompts through the Stitch Photos tool to create the panorama.
However, even without all this, MOST image editing software has SOME kind of "Stitch" option...