Hi Angela,  I can tell you what I know.  When my little one was teething, I was told that there's no real set age for this to happen, but the first tooth usually comes between the 3rd and 7th month. Sometimes later, sometimes earlier. There are sometimes little bumps along the gums that you can feel with your finger and sometimes see. That's the little teeth coming through. My baby started wanting to chew on things and would sometimes just have a rough day of crying because her little gums ached.  I got a really good semi-soft teething ring and that really helped.

Sarah

There is no specific time when your baby will start teething but Sarah is right that they will usually start showing up between the 3rd and 7th months.  You can also see signs of weeks or months before the first tooth actually appears.  Some signs of teething are:
1. Irritability
2. Drooling
3. Coughing
4. Chin rash
5. Biting & gnawing
6. Cheek rubbing and ear pulling
7. Diarrhea
8. Low-grade fever
9. Not sleeping well
10. Cold like symptoms (runny nose, etc.)