Your perspective and location (and thus, that of your camera) can completely alter the way you compose your shot. Do you want to capture a skyscraper emerging from a cluster of smaller buildings? Or do you want to stand at the base of that building, look straight up and show how it soars into the wild blue sky? For the former shot, you'll be far away; for the latter, you'll be very close. And to make either of these images, you'll need the right equipment.
If you have an SLR (single-lens reflex) camera that lets you use different lenses, choose wisely. A wide-angle lens allows you to take in much more of the scene but it also tends to distort (or curve) lines, especially at the edges of the frame. A telephoto or zoom lens will help you magnify a subject that's far away, but its restricted field of view (the amount of a scene that it sees) is smaller than that of a wide angle lens.
Many architectural shooters buy specialty tilt-shift or perspective control lenses, which allow for wide-angle shots with almost no distortion. They're also quite expensive. Alternately, and more affordably, you might shoot a structure with a wide-angle lens and then correct distortion later in a program such as Adobe Photoshop or Lightroom. With just a few clicks, your warped lines look much straighter and truer to life.