I am not smart. power cable: big prong or little prong?

the wire that goes from the fuse, or the wire that goes out from the power switch? which goes to the big prong on the power cable. don't kill me for my lack of knowing things...

On a standard USA power cord,  the small prong is the hot (black) , the larger prong is neutral (white), and the round prong is ground(green).  Hook your power cord hot to the tip of the fuse, hook the sleeve of the fuse to 1 side of the SPST power switch, hook the other side of the switch up to 1 primary lead of your power transformer, the other power transformer primary lead goes back to the white wire.  If you're using a DPST switch, you can switch the neutral if you like.  The green obviously goes to the chassis.

-Richard