Most water seepage issues are due to poor drainage.
Take a walk around your house with an umbrella when it is raining. Take a look at how the water is flowing toward your foundation. See where the water is coming from and how it gets close to the foundation.
If you notice the land slopes toward your foundation, then you have an easy fix that is very inexpensive. Simply get a hard rake and rake the earth toward your foundation so that the water sheds away from your foundation, not to it. Build up the earth so it is higher at your foundation than the yard is. Also, you may want to dig a drainage ditch along your house foundation if the yard slopes to the foundation. This ditch dug along and past your house's foundation, filled with gravel, will allow the water to accumulate in the ditch and subsequently drain away from the house on the downslope.
The cracks in the foundation can be filled with caulking, but I am not sure how effective that would be.
Another way to channel water away from your foundation is to install gutters and down spouts that collect the water and dispose of it away from your foundation. But, this can be an expensive job if you are not a do-it-yourselfer.