Yes, the "Lenna Story" website: http://www.lenna.org/

A permanent link to the TIFF image itself is: http://www.lenna.org/lena_std.tif

Only sort of. Since the image has been in use since before web services etc., more than one different copy was used as "canonical" so it's sort of unsolvable if you want to reproduce work. There has been more recent efforts to pick a reference one, as linked in this thread.

It's interesting that there's so much resistance to stop using this particular image when there are billions of alternatives out there. Lena Forsén herself has asked that people stop using it, which seems like a pretty reasonable request.