Taipei City: http://www.dot.taipei.gov.tw/dot2004/EN/web/map_en921103.jpg
Mapquest: They have a map, but no point-to-point directions. As with most English language map sites, the Romanization is questionable.
Maporama: They offer a decent map. It does include a search function to map from point-to-point. The site is randomly about half English and half French.
MRT Station area maps: they have detailed maps of areas around each station. The maps are not always formatted with North on top, so be sure to check if you orient yourself that way.
Taiwan Map: This site lets you search by landmark or street. I don't care for this site. The map is not detailed and the search function can be frustrating.