How do I find out exacly how much my coins are worth?

It depends on your location and how many coins you have really. If you only have a few coins and don't live near a coin shop, id look them up on here. We also have a free account that allows you to upload your coins. If you are in a larger city where many coin stores are present, id visit them in person. they can look at your collection and make you and offer. Id assume the highest offer +10-15% is the value of your collection. The coins shops will offer to purchase under the true value, so they can turn around and sell the coins and still have room to make a profit.