I need to buy 20 lugnuts. I dont want anything fancy, just something reliable. Is there a certain specefiction of nut I need and where is a reliable store to get them at? Walmart, Firestone, Midas,etc...? If I have to, probably hit up the salvage yard I suppose but would like new ones.

I bought a new set last time I got tires. Try tire dealers and the like. Watch out though, They seem to normally run about $2 a piece.

Parts stores (ie. advance auto parts, auto zone) carry them. A lot of time, price depends on how fancy you want them to look.