Architecture is a different beast. If your talking outdoors then more then likely you going to go reasonable wide angle on the lens and a camera with plenty of movements such as a rail with perhaps a bag bellows. Indoor architecture usually requires lights, light balancing materials, light stands etc to do it right. Do yourself a favor and either checkout a library book on it or peruse the local bookstore for literature. If you just want to do the odd city street thing you might not be hassled, but I've run into over zealous security at downtown firms that made me wonder why I should even do it, and it wasn't that I needed it. Then they call the police and that's another story.