If you don’t feel like building your own arrays of relays, there are many on the market – just google “relay boards”.
Here is a decent example with 8 relays for $34 – http://www.futurlec.com/Relay_8.shtml
This looks even better: http://www.amazon.com/gp/product/B0057OC66U/
If you make your own, I recommend using screw terminals like you see on that board for connecting high voltage wires. But soldering is fine as long as wire is heavier gauge and you have everything very, very thoroughly insulated, protected with strain-relief so connections won’t bend or break, and enclosed in a case or box of some kind.
Just to be safe – show any circuit using AC wall voltage to me first before plugging in.