Cindy Lou Who 32

Ok, I have a 2000 convertible, and I have a small hole in the roof... it's been there since I bought the car 3 years ago, and every time I ask someone about it, I get a different answer, so I'm coming you all of you... the pros! lol The hole is small... like the size of a nib on a pen or pencil, (if it's even that big), how should I get it fixed... where would I take it to get it fixed, and is this a common problem? The hole is close to the back window, on the right hand side, I can't see the hole, but I can find it when water is poured on the roof, or when it rains.

Please someone HELP ME! LOL

Thanks!
CLW :O)