Copyright gives the creators of certain kinds of material rights to control ways their material can be used. These rights start as soon as the material is recorded in writing or in any other way. There is no official registration system. The rights cover:
communicating to the public by electronic transmission (including by broadcasting and in an on demand service);
renting or lending copies to the public; and,
performing in public
Just buying a copy of a book, CD, video, computer program, etc. does not necessarily give you the right to make further copies (even for private use) or play or show them in public. The right to do these things will generally remain with the copyright owner, whose permission you would need. You should note that photocopying a work, scanning a work to produce an electronic copy and downloading a copy of a work which is in an electronic form (eg. on a CD-ROM or an on-line database) all involve copying the work so that permission to copy is generally needed.