How to get a kernel module loaded automatically

Ive replaced the alsa sound modules for sblive with the opensource ones. It says you should put in modules.conf alias sound emu10k1 but this doesnt seem to load up the module. What I havent figured out is what calls this alias on bootup. ( There is also a preinstall for emu10k1 of soundcore ) I can make the alsa ones work ok Just want some info on how the modules are called, and how the kernel/modprobe knows where ( which dir ) to find them. dids