Here are some valuable resources that we have collected for you. Use them and pass them on to others.
Tin Eye - This website will allow you to search the internet for instance where your image has been used. You can upload a photo, or use the direct URL to search.
WhoIs Search Engine - This can search every website in the world to find out who owns it. This is important if you find your image on a free standing website. It can tell you the site owner, the registrar, and the service provider. If I have a free standing website, that is hosted somewhere, figuring out where it is hosted at (The service provider) is important to file an official DMCA take down notice with them. The service provider and registrar is the same thing, is listed at the bottom of the results, and is who you send a DNCA notification to.
Directory of Service Providers - Every service provider must file a DMCA registration with the Copyright Office. This database of service providers tell you exactly who you need to contact in order to inform them that a website that is hosted by them has infringed your copyrighted work. The Registrar and Service Provider are the same thing.
Official link to the DMCA document - This is the official document found on the official US copyright website. Even if you are in another country, if the website agent is located in the US, this applies. If you are in the EU, it has been adopted to apply as well, and every country that has signed the WIPO Treaty follows this same process as the DMCA was drafted off of the original WIPO Treaty.
Photographer's Rights - This includes a set of documents to show what a photographer's rights are for the US, the UK, and the AU.
Contracts and Model Releases - Need a sample contract? What about a model release? Need to know when you are required to use either? This link can provide some guidance.
Property Releases - Need to know when or if you need a property release to take a photograph of a building? This will explain that for you, and provide a sample property release to use for yourself.