Thanks for the answer. You may not realize this but for someone outside the US this can be really confusing. So basically, because of the plurality voting system the battle will usually be between two candidates. And any form of protest vote will go largely unnoticed, because on the level of electoral votes they will always sum up to zero.
One thing though. You say that if none of the candidates get the majority of electoral votes, the House of Representatives decides. Aren't those people that have been elected several years ago? I mean, their political color will largely determine who will win. Then again, I guess usually the third candidate will have zero votes so the top contender always has a majority. Has this procedure ever been needed?