if you want to trademark something, you just need to start using tm on the name, as in "myproduct(tm)". This tells people you have claimed this trademark. If you register it, you change the mark to an "r" with a circle around it, which tells people you have registered it.
Registration is online:
In the US: http://www.uspto.gov/teas/
In the EU:
http://oami.europa.eu/ows/rw/pages/QPLUS/forms/electronic/fileApplicationCTM.en.do
Of course you have to see if anyone has your trademark first:
US: http://tess2.uspto.gov/bin/gate.exe?f=searchss&state=4010:mf5dvq.1.1
EU: http://oami.europa.eu/ows/rw/pages/QPLUS/databases/searchCTM.en.do
Costs $ to process, so probably only worth the effort and cost if you are in business. A lawyer might charge you $500 to $1000 to prepare and submit a trademark application. Trademarks are part of the capitalist system for protecting the interests of good and companies... which might be good, and might be bad 