Hi K.,
I usually hear about people who want to start foods way early ! So you are a refreshing change ! Most doctors recommend around 6 months. If your didn't say anything at his 6 month check up, I'm wondering if he had one ??? (Or maybe your doctor just assumed you were an old pro and didn't tell you ? i.e. do you need a different doctor?)
I also wondered if your son is trying to sit up or not ? Usually by 5 months they are trying to sit up, and somewhere around 6 - 7 months, they are sitting up by themselves. I used to let mine sit on the floor with pillows behind them, cuz they would lose their balance and tip over onto their backs. I'm hoping the rest of his motor activities are good, so this isn't a concern. but if he isn't sitting up and moving around by 9 mnnths, I would definately call and ask the doctor.
Anyway, food. When you start "real food", you should start with one food at a time, because that way you can watch for allergies. i can't tell if you've started cereals or not, yet, but usually they recommend rice cereal first, and then add fruit with it, I used to mush up a banana, or buy regular applesauce and mix it in with the cereal. (it helps with the bowel movements that firm up on food)
If you have a blender or food processor, you can grind up the meal you are feeding the family, and let your son eat that. You may have to add a little water when you do that, to some things -- like meat which can get kind of pasty. But all in all, the "real" people food will have a whole lot more flavor than the babyfood stuff, and it's a cheaper way to feed him.
Does he have teeth ? If so, whole grain cheerios are a great way to help him practice picking up food (say from his high chair tray), and putting them in his mouth. I think I may have given them to my kids before they had much for chewing, but they can gum them to death, and they have fun picking them up and feeding themselves.
Kids like to grab for the spoon, too, so I had a plastic spoon ( a baby one, not a regular one, so it wouldn't break or splinter) for the baby to hold. They can't navigate it to the mouth very well, but it made them feel like they had something to hang onto.)
Your doctor's office probably has a nurse who would be able to provide a whole lot of info on starting foods. Nurses have more nutritional training that doc's, so that's who I would ask.
And, wow ! Your household sounds busy !!! I had four kids, too, but they were spread out in 2's. Have an awesome day !
Barb