Venus, brighter than all other planets and stars, will dangle just below the thin crescent moon in the southwestern sky. It'll be visible -- impossible to miss, in fact -- just as the sun goes down, assuming skies are cloud-free.
Soon thereafter, Mercury and Jupiter will show up hugging the south-southwestern horizon (just above where the sun went down) and extremely close to each other. Jupiter is very bright and easy to spot; Mercury is faint and harder to see, but it'll be apparent by its location just to the left of Jupiter.
Jupiter and Mercury will set less than an hour after the sun, so timing your viewing just after sunset is crucial. You'll also need a location with a clear view of the western horizon, unobstructed by buildings, trees or mountains.