These I find very helpful and they are a good reference. The Matoran Universe Map was released in the book Bionicle: Makuta's Guide to the Universe and the Map of Bara Magna was released in Lego Magazine.

Remember to click on the image for full size. The map of Bara Magna is signifigantly bigger than the map of the matoran universe. this may suggest that it is 'to scale'

Also, it is very difficult to read the captions when the images are not viewed at their full size