How much do I feed my baby?

My baby boy is just over 6 months. He's started to develop quite a bit of an appetite so now taking a whole jar of heinz baby vegies at lunchtime. He has decided he still wants the 4 bottles (200ml) per day too but will wake every 4 hours to take it. So we thought maybe we should start him on more solids & began giving him a 2nd jar of heinz vegies at dinner (tea) time, usually around 5-6pm at the latest. We've only done this on 2 occasions so not expecting a miracle straight away but he's still waking for his 4 hourly formula feeds. Maybe I need to give him fruit or custard on one of the meals ie lunch or dinner? What am I doing wrong?