qemu tutorial?

[Tim Kellers]

I'm feeling a bit _thick_ here.  I can seem to get through my brain the 
process of creating an .img file with qemu that will boot.

I can create the .img file, but how do I get an OS on it?

I've got a feeling this is a simple thing, but I'm apparently too simple to 
see the path to a bootable image disk.

Could someone point me to a "Howto" for creating bootable .img files for qemu?

Thanks

Tim Kellers
CPE/NJIT