If this is something you're just starting on (panos), you might also consider Windows ICE and Photosynth. Free and quite capable. Not what a pro would use, I'm sure, but it gets you up and running quickly with fairly good results. If it's something you find you want to pursue further, there are a number of paths you can take at various labor/expense levels and you'll find various user groups on the net devoted to panorama photography. I've used lenses from 8mm fisheye to 200mm (on a crop camera) and try for a minimum 25% overlap between frames. ICE does a pretty good job stitching all together. It's not always perfect, but being a hobbyist with a full time job and other interests, it's good enough for my enjoyment. YMMV. I post on Photosynth as 'emag325', you can check out what can be done fairly quickly and easily at the amateur level. PTGUI is excellent, but as a hobbyist, I don't feel the need to spend much on pano software......although it would be my first choice if I do.