If you have a high water table or it has just rained you may find that your footing holes have filled up with water. This is not usually a problem. Make sure that your footing holes are dug below the frost line for your area. You should use a pump with a hose to remove as much water as possible. You may use a barrier or form tube such as Big Foot to keep the water out of your concrete pour. The bell shape of the footing form will help keep the footing in place and prevent it from floating up to the surface. Once the footing is poured you may want to back fill some gravel around the footing to promote drainage. Concrete poured in wet conditions will actually have more strength. The slower that the concrete cures, the stronger it will set.