A baby 6 months old is at a stage where they can start eating new foods if they have not started them already. Some parents start with cereals and first stage baby foods at four months. If you have yet to start, 6 months is a good time to get them going. By now you may notice they watch you eat with great interest, and you will notice they want to try it too. As long as they can sit with assistance, they are old enough to start. Make sure you start a new food and then wait four days before starting a different one in the event they have a reaction. This allows you to know which food caused a problem.
Food is not the only exciting thing for your baby right now. A baby 6 months old should be working on sitting up on their own, if they are not doing it already. They may not master it just yet, but they should be working on it. Sit them up and let them go, with your hands very close to them. They are going to wobble and fall at first. That is normal. They will learn to adjust by using the right muscles to hold them up. Now is the time to encourage them to sit on their own and you can say good bye to some of the younger baby items you may have, like the bouncy chair.
Crawling is something that some will do near this age, but not all. However, a baby 6 months old should show some signs of wanting to get moving. Some mellow babies may not see the point, but they will soon enough. Make sure they get plenty of time on their bellies so that they can push up with their arms. Some will arch their backs with their legs in the air, which may seem counterproductive to crawling. However, this shows a motivation to move. You will soon notice they try to push their feet on the floor to move forward. Do all you can to encourage them and have them on the floor quite often.
A baby 6 months old should also be trying to talk to you. They can not yet say words, but they should be mimicking sounds in an effort to communicate. Some babies mimic coughs and even sneezes to get your attention. They should be saying some simple sounds while they are babbling. Encourage them by repeating what they are saying and talk to them often. This helps greatly with language development. If your baby is not babbling or making any noises, talk to your pediatrician about having a hearing test done.