How can I create simple shipping modules?

Maybe this is a noobish question, but I did not readily find the answer via search.

I have a store where shipping is calculated manually after checkout. I would like to make a super-simple shipping module (or series of shipping modules) that has no price so I can at least let the customer choose a preferred shipping method even if the price is unknown. It will basically be a series of free shipping shipping modules with different names and no price shown.

Can somebody tell me which files need to be copied to create a new shipping module, or point me to a thread with a tutorial?