How can I improve air flow in my basement?
If it's a really old house, that might actually work to your benefit as old houses usually are not well sealed when compared to new homes which are practically air tight.

There's a couple components to what you are trying to accomplish:


Air circulation - A ceiling fan will probably do the trick for a single room.  If the house is conditioned via forced air, another option might be setting the furnace fan to be always on instead of only on when heating/cooling.  This will help keep the air circulating throughout the house (and through the furnaces filter).
Humidity - If its really bad, a dehumidifier will likely be required.
Fresh air - In all likelihood, you are probably getting a decent amount of fresh air through the cracks in the walls and elsewhere already (seeing as it's an old house).  If you are not, the simplest solution is to open a window ocasionally. If this is not an option (ie: winter) then the furnace fan trick I mentioned in (1) migtht help too.


Some other options are:


Some household plants might also help with the air quality - talk to your local garden center to see if they have any ideas
Air ioniser (or negative ion generator) - I can't backup any claims made by these devices, but some people claim they work well.
Install a small HEPA filter