Teething typically starts around age 3-4 months. You will notice your baby's increased drooling and dribbling. This increase in saliva will make babies vomit and spit up more frequently, have loose stools or develop coughs during sleep. For relief of discomfort have your baby chew on a hard roll, teething ring, cold carrots.
Here is an eruption guideline and what to expect when:
6-7 months: 2 lower front teeth
7-12 months: four upper front teeth
14-16 months: 2 more lower front teeth and four molars in the back
18-21 months: 4 eye teeth
24-30 months: 4 more molars in the back.