Use your favourite search engine to scan the web for the keywords SATB and TTBB, which are abbreviations for choir voice arrangements. The first one is soprano / alto / tenor / base, and the second (I think) is tenor / tenor / baritone / base.

Some of the links you find will lead to free on-line vocal arrangements of traditional stuff; others will lead to retailers of such arrangements, but the prices are quite economical from what I've seen.