Some parents start their baby on solids as early as 3-5months old. We waited until Rocco turned 6 months before we introduced solids to him. He is highly allergic (like me) so his pedia advised us to wait until 6 months so his body would be more ready to accept solids.
I was actually bent on grinding our own rice and cook the cereal for him, but I haven't researched much about it, so I just bought Healthy Times organic brown rice cereals from Healthy Options. So expensive! I hope to find a better alternative that would also be as good.