Ross -If you want to reserve copyright on your own images and files, its always a good idea to at least include a copyright statement. Technically though, the date that you upload those images and files should be sufficient for a copyright. It works the same as mailing yourself a copy of a document and never opening it. This is not a legal copyright, but should serve to prove when you created or started using them. (If you are rally serious you can officially reserve rights via copyright, trade mark or other method)
With regards to Microsoft and other trade names, check out their website for this info. Usually if you are using a name, or image that they own rights to, they will have a stipulation for useage, size of image, where to include the little "r" and "tm" and "c" if needed. If they do not stipulate terms of use, ask them via e-mail.
