Tue Aug 19, 2008 6:05 am by Zalbor
Didn't it say somewhere in the homebrew channel's readme? Anyway...
You have to create a folder in the SD card called "apps". In that you create a folder for each program you want to try, and put the program's files (usually only boot.elf or boot.dol) in that folder.
Another way is to use wiiload, which is packaged with the homebrew channel, to send the .elf or .dol file from your computer if it and your wii are in a network (this way won't work with programs that have more files than one).