If you look west, shortly after sunset, Venus is hard to miss. It's a bit south (to the left, if you're in the northern hemisphere) of the spot on the horizon where the Sun sets, and up about 10 or so degrees, roughly the width of your fist held at arm's length.
If you wait a few more minutes, and look a bit up and to the left of Venus, you'll see Jupiter. Normally Jupiter is very bright, and obvious. But it's on the opposite side of the Sun from us now, over 900 million kilometers (575 million miles) away. Worse, it's near the horizon, so the twilight dilutes it, and if you have any pollution or haze, it's dimmed even more. Being so close to Venus in the sky doesn't help either!
And it'll get closer. Over the next few days, Venus and the big guy will draw ever closer, and on Thursday night they'll be about 1 degree apart-- the width of a finger held at arm's length! That's pretty close.
In reality, they're about 750 million kilometers apart (about 470 million miles). Venus is brighter because it's a lot closer to us. But our lack of perspective makes them look right next to each other in the sky. They don't get this close very often, so this is a real treat. Since they are also the third and fourth brightest objects in the sky (after the Sun and Moon, of course) this apparition, as it's called, is even more spectacular. You can read more about this at the Sky and Telescope magazine website.
Every day, if I can, I'll take a picture and post it here so you can see them getting closer. The picture above was taken in my back yard on Sunday night, August 28, an hour or so after sunset. Click it for a higher-res version. At that moment, the planets were about 6 degrees apart.
Now stop looking at my picture and go take a look for yourself!