Proper age to introduce rice cereal?

[Onelastkissfromyou]

My baby was 8lbs 8oz at birth he is both breast and formula mostly breast fed he now weighs almost 14lbs hes going to be 3 months on sept 10th hes teething already and when i give him the tablets he opens his mouth for my finger and swallows, he smiles, coos, has been sitting with help for awhile now, i was just woundering what would be a proper age to introduce cereal to him? Thanks everyone
It seems like nothing is satisfying him though