Babies are breast fed till they are about 4 months and after that it is adivised to feed them juices and semi solid foods. There are many ready made baby foods available over the counter as semi solid and solid foods.
Home made foods are the best which can be given and the foods which our ancestors have provided were always healthy.
We, keralites, usually have a function for the baby when it is 6 months old called "Choroonu", that is feeding baby rice for the first time in its life. We usually have the eldest member of the house like Grandfather or uncle feeding the baby at the temple or at temple. This is also called as Annaprasanam in some places in South India.
After that the baby will be fed a teaspoon now and then. By eight months we will be able to feed rice as the main food for the baby along with mother's milk.
The rice will be cooked very soft and mashed nicely with a spoon or hands. A teaspoon of ghee will be added and mixed well with this paruppu curry. Take papad along with this and feed the baby, you will see the crankiest of babies will have this food gleefully.
Follow the Paruppu Curry recipe here to prepare and feed the baby