I just also wanted to add that there is a camp that is pretty anti-rice cereal, mostly because it has very little nutritional value, just empty carbs. The APA (American Pediatrics Association) and WHO(World Health Organization) recommends that babies be exclusively breastfed until at least 6 months, and recommend that they be breastfed until over a year- WHO even says 2 years.
Here is a good link about starting solids from a site that I like a lot called kellymom.com. http://www.kellymom.com/nutrition/solids/index.html
In my own experience, my daughter hated the baby oatmeal and cereal- and I don't blame her- taste it and see... its awful. I learned to try whatever I was offering her- ever taste formula? Ugg. And that helped me decide what she was getting fed. We delayed solids until 9 months of age, and her first food was a green bean- straight from the table.
She showed an interest in food by "tracking" us when we were eating, trying to imitate our eating actions, and if she was on our lap while we ate something, she would parrot the opening of the mouth like she was expecting the food to come to her mouth, instead of ours.
As it is, we use some baby food, but mostly give her what we eat- we cook without salt, and add it to the adult food later if we want it.