As Henry said, there's lots of info on the Forum on this subject. If you use your Browser's FIND feature, try using words like 'crawl', or 'basement', or 'water'. Don't give up; there's lots of info there.
One recent sample is Basement Moisture. In this particular post, I went to some length to explain how to diagnose the possible source of water/moisture in the basement. If you need more info, post up.