Google comes in handy for things like this. Lots of info available, including:

This link has pictures that show stations signs in Japanese and English:

http://hisaai.hp.infoseek.co.jp/Nagoya/index_eg.html

You can find a map with the station names in Japanese and English here:

http://www.kotsu.city.nagoya.jp/tagengo/subwaymap.pdf

and general information here:

http://www.kotsu.city.nagoya.jp/ (Click on "English" at the top)

Based on my experience in Japan, as someone who doesn't speak Japanese, if you can navigate a subway system in the US, you shouldn't have any problem doing so in Japan.