Looked like a good resource to post, I will be looking into it more.
http://nfgworld.com/mb/thread/1071-The-NFG-Book
http://howtonotsuckatgamedesign.com/?p=3272
http://books.google.com/books?id=6isWHHPii84C&pg=PT121&lpg=PT121&dq=pixel+art+PC-Engine&source=bl&ots=TlEEhYJBI9&sig=YhNWdURove5OnK1WwubIPw2uQd8&hl=en&sa=X&ei=Z_hdT66QHeXKsQKZ3rCvDQ&ved=0CEMQ6AEwBDgK#v=onepage&q=pixel%20art%20PC-Engine&f=false