Hi Patrick,
Bad luck about the dust. For dust spots on your existing photographs the best you can do is use your favourite photo-editing software to airbrush them away.
To help prevent this problem in the future have a look at Gordon's
Camera Labs Digital SLR dust workshop and, in particular, at his
Camera Labs DSLR dust cleaning technique article.
Your manual has good information on dealing with dust. See page 112 about "Appending Dust Delete Data". Page 114 tells you how to raise the mirror if you want to use a blower in the way that Gordon describes.
Bob.