Telling too much online.

As I first began to use the internet, which i was a beginner, I was playing cribbage in a online room. The other person that i was playing against started a conversation with me, how many kids, where you live, what you do for a living etc... Being new to the computer world I addressed her questions (could of been a he not sure). Few days go by and I go and start to play in the game room. When your in there you can keep a friends list so you can see when a friend comes on. Well up pops my new friend from the previous day, telling me that she went to the webpage containing the name of where I'm at. Through that webpage she found the school webpage, and in there she found 1 of my children since I said that i had a handicapp son. It scared me that a person would spend that much time looking up a person's info and accually finding it and knowing alot more about me. After that I made sure not too give too much info out to anyone and be lery of talking to people who I do not know...