I heard that some people have been arrested and charged with "transmitting money without a license" for selling Bitcoins.
Does this mean it is illegal for me to sell my Bitcoins?
There is no such rules to make license for bitcoin business. It is completely decentralized and no institution have control over it but yes they could ban bitcoin but they can't force us to make license. That guy who got arrested might be fool and might not have much knowledge about bitcoin business. It's totall fake report but in many countries bitcoin is banned so it might be case of those country.