Do you want to show your architectural expertise? Study this very compact and concise Guide to Residential Styles provided by the National Association of Realtors. Just pick the style or picture for a concise description of type. Also click the Structural Elements link on the page (I can’t get an external link to work) to learn to identify arches, columns, windows, dormers, roofs and molding.
Of course you can always go to Google for a search. The first result for a search on “four square houses” (a very popular style in Midtown Memphis) gave me this interesting Wikipedia article, but other results are numerous and detailed.