When is this due, and what level of school is it for?
My thing was Spanish lit, so I don't know about Eliot specifically, but the best thing to do is probably check out a biography on him and a collection or two of some of his works from the library. If there's a good selection, look for books that aren't too old, maybe ones that were published within the last 15 years, at least to start with. Read the introductions, skim a few of the poems, see what images/devices are used frequently, try and get a feel for his style. Then look at some of his better-known works and decide for yourself what you think is most representative.
You really need to figure out why you feel the one or two poems are representative of his work, not what everyone else thinks, and I think the only way to really do that is to acquaint yourself with the work and the author.