I have been collecting old coins as a hobby and a business for years now. As a child I recall the satisfaction of working hard mowing lawns, doing chores, and helping around the house to earn my allowance. My father would pay me in currency I could easily save or spend at the time in retail stores and he would also give me a little bonus (incentive for doing a good job on my chores) in the way of old coins with some collector value.
My father started me off modestly typically giving me old coins that were cool like buffalo nickels, wheat pennies, and mercury dimes. He would instruct me in the importance of saving and also the importance of an understanding and having appreciation for old coin values. I started collecting and filling coin books. This led to trading, bartering with friends, and frequent trips to the local gun and coin shop where I could buy and sell my coins and get help figuring out some of my old coin values.
I must have made a few hundred trips to that store and would look for new old coins walking up and down the aisles. I established a relationship with the sale people and also the store's owner who was an expert in guns and old coin values. He could look at a coin and within a minute or two, without looking at any books or charts and get within 10% or so of the value of any American old coin. He could always be trusted helping me determine any of my old coin values.
Since the early seventies I have collected old coins and have traded and bartered my way to a healthy second income for my family. Much of the strategy has been buy and hold using time to increase my collection and old coin values. As with any commodity look for buying on the low and selling on the highs. Consider concentrating in collecting old coins with high scarce metal content like silver and gold.
Old coins and old coin values change and fluctuate with market conditions so keep an eye on your collection and be diligent in keeping it current if you want to make money and run your hobby like a business.