1998 Honda Civic water leak

Interior problem
1998 Honda Civic 4 cyl Wheel Drive Type unknown Manual 98000 miles

I have a '98 Honda Civic. A couple of weeks ago, after a rainy night, I noticed the front and back of the passager's side were wet. I thought it was from a bottle of water that I had left in the car. But now it's been rainning for 3 days and I have again water in the car, a lot of water. My questions are: Does anybody have any idea how did that water get in the car and how can I fix it? And where can I take the car for somebody to fix it?