You can set security which will prevent Acrobat from printing, or allowing copy/paste.
Any file can be emailed, copied, forwarded etc. by definition.
DRM solutions control whether the copy can be opened, if you have a 5-6 figure budget, full time server, technicians etc.
If you're actually creating 'eBooks' and need rights management then PDF is probably not the best choice, as LiveCycle DRM means the file can only be opened in Acrobat or Adobe Reader. Formats such as EPUB are more widely supported on mobile devices and can also be rights-managed. Selling through an established vendor they will often have a DRM workflow set up for you, but as Test Screen Name says if you're running the server side yourself it becomes a huge investment.