Remove stuck drawer by prying it open with a small screwdriver or butter knife. Empty drawer, turn it over and inspect it.
If the bottom of the drawer has bowed, remove it and reattach it upside down. If no bowing is apparent, add more nails to secure the bottom or hammer in any nails in that appear to have loosened.
Run a lubricant such as candle wax, paraffin or soap along drawer runners, located under the drawer, if the dresser has them. Sand runners if lubrication doesn't work.
Replace drawer in dresser.