I googled fluoride but couldn't find any actual studies showing fluoride prevents tooth decay.
It seems you're not doing it right. Don't just google "fluoride", but instead try searching for something more direct, like "studies showing fluoride prevents tooth decay", or going to a site (such as Wikipedia) that provides references.
Here's a paper showing that fluoride prevents tooth decay: http://www.ncbi.nlm.nih.gov/pubmed/17891121
You can find more here: http://en.wikipedia.org/wiki/Water_fluo ... ence_basis
Every article I can find says fluoride can be a poison if too much is ingested.
You realize that this is true of most (if not all) things we ingest, right? You can die from drinking too much water, even unfluoridated water! You will die if you breath too much oxygen. Most vitamins and supplements are toxic in large quantities.
I do not want to take the chance with any toxic substance so I have purchased a reverse osmosis water filter but it is sad that our government trys to force these things upon us.
Good luck with that. It will take a heck of a lot more than a reverse osmosis filter to protect you from all toxic substances. You'd pretty much have to stop eating, drinking, and breathing. It's reasonable to question whether or not we need
fluoridated water, but its safety is well established.
Go watch "Dr. Strangelove" and see which side of the debate makes more sense.