fully pumped membrane waterproofing system would probably be the best bet if you intend to use it as habitable space...
http://www.***.com/faqs-basement-w ... ment-work/http://www.***.com/basementwaterproofing.phpbut if its just a storage area for tools, installing an automatic sump pump for times such as now would be a good idea, although finding out how the water came to be there in the first place would be a good start, it could be a high water table, broken pipes, drainage, airbricks to close to the ground...
theres various sites containing loads of info on basement waterproofing, its a big subject...
the peter cox site is pretty informative..