Copyright law protects, essentially, artistic expression. It exists, for example, in literature, paintings, sculpture, and architecture. Copyright protection can be "thin," meaning that the work contains mostly facts or ideas, and not much artistic expression. But even the white pages of the telephone book enjoy minimal protection. Maps are also protected, as are computer programs (as "literary works")..
Unlike the patent right, copyright can last a long time and the determination whether a given work is still protected is, depending on how old it is, somewhat complex. See http://www.copyright.cornell.edu/public_domain/.
You have copyrights without having to do anything beyond creating the work. However, you cannot enforce your rights without registering the work. Also, if you register sufficiently early you may obtain "statutory damages," i.e., a minimum damage award without proof..
Of all the mechanisms for intellectual property protection, copyright registration lends itself best to DIY, is minimally expensive, and least prone to error. So an attorney's role in assisting clients with copyright matters is typically in the area of Enforcement.