How can you get copyright pictures?

The question is unclear as to your intentions.

If you are creating pictures and wish to have them protected by copyright, you don't need to do anything: permission is automatic as soon as the work is fixed in a tangible medium. If formal registration is available in your country, you may choose to do so, but it is not required.

If you wish to use pictures that are someone else's intellectual property, you need to ask them for permission. Many photographers make their works available through licensing clearinghouses like Corbis or iStockPhoto; others must be contacted directly. Typically this is done in writing, and is specific to the immediate use.