Google images can get you to plans and elevations very quickly. However, make sure you choose plans from a VERIFIED SOURCE.
What's a verified source? In the search below, I looked at web addresses to see who posted these plans. Some were probably copied from books and placed online, others were recreated in Sketchup. For research, make sure you use sources that you can verify validity. Don't trust a blogger to get it right or another student to redraw plans accurately.
Verified sources can include URL's with .edu at the end. Libraries, museums, and other cultural institutions make research information available online, as well as architecture firms and the buildings themselves that may now be house museums.
Great Buildings is a digital compendium of architecture plans and images from Architecture Week, a verified source. This is a fabulous verified source that provides further sources on each page about that work of architecture. See the example below:
