Maps of Buenos Aires
Mapa de Buenos Aires v1.5
The Goverment of Buenos Aires released a public Map service that allows you to navigate the city and find important landmarks and places you might want to visit. You can search for NLI properties on this site using the street intersections provided in the title of the property.
Maps @ Argentina.com
There are several other map sites (not as complex and thorough) that may help you find points of interest.
Argentina.com has a very useful search engine; you can use it to search for addresses, banks, libraries, hospitals, theaters, etc.
Provides the map to their network of subways across Buenos Aires.
You can search for any subway line.