Without a picture, it sure is hard to try and make a diagnosis. Frankly, even with a picture, it can be difficult.
In order to post pictures, they have to be hosted first.
Free hosting sites would include--
http://photobucket.com/
http://www.imageshack.us/
(I personally prefer imageshack)
Then, this topic explains how to post the hosted photos--
http://tomatoville.com/viewtopic.php?t=444
If done correctly, "You should see the actual image show up in your post when you preview it."
From what you've described, you might want to have a look at images of septoria leaf spot or bacterial spot as possibilities. A Google Images search can be helpful in that it will show you several different pictures and not just one or two like the TAMU problem solver and other links might.