The Photos:
Make very sure the tripod is level, I use an actual carpenter's level on mine before shooting photos. A level tripod will result in less of the image height being shaved off when rendering the panorama.

Once you've taken your 16 or 18 (depending on your tripod markings) photos, and they're all in good focus, you should resize them all to something like 640 x 480 pixels each. Although your camera probably takes much larger photos, larger photos don't do much more than make the resulting ".mov" panorama file much larger than it needs to be causing a longer download time.

Start up Quicktime VR Authoring Studio (it will start up in Classic Mac OS 9 mode).

Then click File -> New -> Panorama Stitcher to create a new panorama.

A dialog box will pop up where you can click the "Desktop" button (or choose another directory if you want) and then click the "New" button. Here you can name a folder you want your QTVR project to be stored in, "My QTVR" in this case, and click the "Create" button. Then you can name the panorama file whatever you want (replacing "untitled") to and click the "Save" button.

At this point you should be presented with an empty panorama stitcher window.

Now click on the "Image Alignment" button.

Set the "Degrees Between Images" value now. Divide 360° degrees by the number of equally spaced images you've shot. For me, with 16 images per panorama, this equals 22.5° degrees.

Then click on the "Settings" button, to the right in the Panorama Stitcher window.

Here you can set the "Panorama Viewing Size", in this case 320 x 240.

If you want to make a 180° panorama (half) set the "Default Pan" to 180.0, otherwise (for a full 360° panorama) leave it set to 0.0. There is no need to change anything else here.

Now you can add your photos to the Panorama Stitcher. You can do this by clicking the "Add Images" button, or you can simply drag and drop your photos into the window.

For a full 360° panorama we add 16 or 18 photos, depending on the number of markings on your tripod head (mine has only 16). If only making a half panorama of 180° we would only add 8 or 9 photos, and would also uncheck the "Images Wrapped" checkbox over the Add Images button.

After all of the photos have been added click the "Stitch Pano" button to create the QTVR panorama. If you've gotten the settings right, it should do it's work and render the panorama with no errors. If this happened you should be presented with something like the following ".pano" file.

Here you can click and scroll through the panorama until you're at the view you want to be the default as soon as it's loaded. You can also set the amount of zoom using [shift] to zoom in and [ctrl] to zoom out. Once you're happy with how it looks click the "Set Playback Settings" button. Then rename the panorama file with a ".mov" (instead of the ".pano") extension and you're done.

You can now embed your snazzy new QTVR panorama in a web page on your site using some very simple HTML code (the same I use on my own site), something like the following.

<embed src="panoramas/myCoolPanorama.mov" width="320" height="256" controller="true"></embed>