homesharing is for sharing itunes amongst other computers in your home not ipods.
so you have a pc in your bedroom with itunes and all your music, and a pc in living room with nothing
install itnes down stairs enable homesharing upstairs and both Pc's can play music in your library.
on an ipod touch / ipad synced to a diffrent library open itunes go to settings Music then enter the detaisl you used when sharing your itunes library (normlly same ones you use to buy stuff, has to be an apple ID close music down (or reboot) ipod touch/ipad and now when you go to music you will have the option "shared" under the more button.
not sure if possible with normal ipods