Ginger is generally used to treat nausealack of appetitediarrheaindigestiongas entrapment. Also it is known to be very effective in treating upper respiratory infections.

It is known that pregnant women who eat 1 gram ginger every day don't have morning sickness. It is particularly effective against car sickness. This is because ginger helps to ease the symptoms of motion sickness.
It is also known that children who are given foods with a little ginger added experience less reflux related problems. Ginger tea is good for common cold also.

If you want to introduce ginger to your baby, you may add it inside mashed pear or winter squash or carrot in small amounts after your baby is 8 months old. After she grows up a little more, you may also add it to the home made lemonade you prepare for her.

If you want you can also add it to your dish as well. You may add ginger while cooking. It will have a stronger taste if you add it when your dish is almost done. If you want to dilute it, add it right at the beginning of the cooking process so that it cooks well.

Keep in mind

You may buy either fresh, dried ginger and ginger in powder form. The best one is fresh ginger. Prefer the ones that are lighter brown or cream. You may store fresh ginger at ambient temperature.  
If you did buy dried root ginger, try to chop it in direction of fiber.  

You can add sliced ginger to your salads or add hot water on it to prepare yourself a ginger tea. 

You may use ginger in powder form as spice. 
Nutritional value per 100 gram of ginger;
Vitamin C 5.0 mg
Vitamin E 0.3 mg
Folate 11.0 mcg
Calcium 16.0 mg                                                      
Iron 0.6 mg
Magnesium 43.0 mg
Phosphor 34.0 mg
Potassium 415 mg
Sodium 13.0 mg
Manganese 0.2 mg