There are several ways to waterproof your basement. You may want to waterproof from the inside, or you may consider waterproofing the exterior. There are paint-on types of waterproofing as well as drainage systems.
The first thing that needs to be done is outside landscaping. You need to make sure the soil slopes away from your home. You also need to make sure the down spouts are extra long so the water is carried away from the basement. Keep the gutters and drainage pipes, and grates open and clear of leaves and debris. There are also many types of drainage systems, such as French drains, that can be done to keep the water from collecting around your house, thus eliminating seepage into the basement. You can also buy exterior wall sealers. However to use these you will need to dig down to expose the foundation.Although not really waterproofing, many people use a sump pump, to get water out of their basement. This works well if water is actually pooling in the basement. You can buy interior wall and floor sealer products at your local home improvement store. These are good if the water is not leaking but rather seeping in to the basement through the cement. They are brushed on just like paint, although any painted surfaces will need treatment before applying the waterproofing.