It should work ( the Canon fit) and costs about £90 non APO. The better APO version you want costs about £30-40 more (worth it IMO)
It is a budget Zoom which is VFM but will not give costlier faster lenses with IS any bother. At f4 you will need a tripod at the long end and its macro is a 2:1 ( not "true macro") but still capable
A simple search on these forums will give you examples of images taken with it
A recent one http://www.avforums.com/forums/showthread.php?t=507555&highlight=sigma+70-300
One thing to do is find out if it will work well with a D60.
The "Error 99" lens incompatibility reffered to older sigma lenses with the 300D and 10D ( not newer lenses) but an email enquiry to Sigma would be reassuring
mine arrived this morning from onestop (linked above) - i must say i was a bit apprehenisive about ordering from China, and i'm not sure the saving in £ was worth the knots in my stomach, but now it's here and everything is fine I think I would do it again.
One stop were very quick and good communication, i paid 114 last week.
There's a s/h one on ebay for £85 which is quite tempting. Item 260108454758. Otherwise my money will go with Onestop. But I'm having a hard time working out where my lens budget should go at the moment.
I'm trying very hard not to buy one and save for the Nikon 70-300VR instead, but at 1/3 of the cost it is tempting. The only problem with the Sigma is that it's soft @300mm unless you stop down a bit, I know that I could not hand hold and that focal length either.