I found this really informative site which has a DIY for cylinder head porting. There are tons of pictures and examples. Although they use a V8 cast iron head as an example they give tips on how to work with aluminum heads as well (like hondas). I haven't done this myself but am planning to do so next summer when I build my engine up. I'm sure this could be very usefull for other people on here.
Go check it out on '' http://www.sa-motorsports.com/diyport.htm ''

Go grinding away!!!