If you haven't already, I would start here to get up to speed.

https://bitcointalk.org/index.php?topic=15918.0

The links in that first post should be a good bit of reading and get you started in the right direction.As for the copyright question, I am not sure. From what I have read it looks like you may be able to make use of graphics that are made available to the public domain (or any free use license) without issues but do not take my word on that.

Check the following thread for discussion on the graphics and copyright/trademark issues https://bitcointalk.org/index.php?topic=128254.0