Hello, I hope nobody gets mad that I'm posting here ~ tempotopaz.com 's forums weren't much help

I hope you guys will be able to help me some. I have a 1990 AWD Tempo. It's my baby. Today, I watched my temperature gage climb to HOT ( I didn't have the AC on or anything. there was nothing I could do about it.) I heard a crying or a moaning sound, and then I saw the smoke coming out from under the hood. I managed to get off the road and lifted the hood. A rusty colored liquid was just a bubbing out from around the radiator cap and all over that section of my car. I called a wrecker (paid an extra 100 bucks for a flat bed wrecker - normal tow truck would have wrecked my four wheel drive stuff underneath.) and now it's just a sitting at national tire and auto parts waiting to be worked on. Any thoughts on what this could be, what I need to do, and what I need to expect? Thank you.