Hi & welcome to Pixalo
Fair few people have opted for dedicated wide angle lens to get 10mm, with the Sigma 10-20mm lens . Link here :-
http://www.pixalo.com/reviews/showpr...duct/60/cat/14
or are you after something like this ?
WIDE ANGLE FISHEYE LENS FOR NIKON Digital SLR D40/D50 - (eBay item 300154546630 end time Sep-30-07 16:06:46 PDT)
Re trying to get to 600mm , note with the crop factor of the cameras sensor , this would be the equivalent of 900mm in old 35mm SLR days
That's gonna need a tripod to stop camera shake showing & as stated by Silkstone, shooting at f/11 is going to need a pretty bright day to get anywhere near a shutter speed that is useable.