Devon,
I can't give you legal advice on copyrights, but there a a number of high quality stock image sites on the web where you can get images. An example is the search I did at Eyewire.com on castles in the category of photography:
http://www.eyewire.com/cgi-bin/WebOb...=6&search.y=10
These images use rights can be purchased for a nominal fee. The final version you receive is much larger than what is shown on the page. I've always gone with the low resolution version and it's been more than enough.
There are many others, but Eyewire.com and the two below are some of the best.
PhotoDisc.com
GettyImages.com
Be sure to look for royalty free images. Those that are royalty images carry an ongoing charge.