How?????
Make a copy and put on the bottom...copyright SkyDancer(real name) 2009 and sign and date.
That is your copyrighted copy of the material. It proves you wrote it on such and such a date, and ou retain the right to reproduce it. If anyone else does and claims it has their own, you can sue.
Most material is self copyrighted now, with just adding a copyright symbol, lower case c with a circle around it.