I also have a very damp basement which I will be turning into a poker room.. The first thing you need to do is find out if any water is coming into your basement or seeping through... It might be humid because of condensation through the cinder blocks..
Look on the internet for free estimates for someone to come over and give you prof. advice.
All you might need is a strong dehumidifier or a ventilation fan installed.
In my case I have insulation behind the wall thats soaked.. I haven't figured out what to do.