Step 1: Create an imagefield to use later
If you already have a CCK imagefield setup for a nodetype, which can handle multiple images, you can skip this, but you still need to know the machine readable name of your field.
...
Step 2: Setup jCarousel Block in the admin/settings
These are the only required fields:
image field name: yourfieldname
image field type: imagefield
no need to specify thumb prefix.
Step 3: Upload images
edit node and add the images...
save
Step 4: Check block settings
Of course you need to set the block to the region you want.
That's it!
Step 5: lightbox (optional)
You can enable lightbox if you have it.
The screen shots of the settings are at #310580: Documentation with images for imagefield .
NoteSome users have left comments that this doesn't work, but there were no specifics given.