When Arianna turned 6 months old (way back in June 2008), I started with these (in that particular order - every 3-4 days)
~'air zam zam' (usually it's cooled boiled water)
I did not cook the porridge, ie cook the rice real soft, and blend it like (I think) my mom used to do. Instead I milled the white rice, brown rice and barley into fine flour (imagine the Neslac in tin), and cook it: 2 tablespoon to 3/4 cups of water. I then dilute it with a little bit of EBM to give it a familiar taste.
I did not really puree (blend and sieve) the veggies. Instead I just used the blender/food processor till the food is real fine. Malas la guna sieve :) Plus you're gonna sieve out all the fibre bits.
For the fruits, the soft fruits like papaya, banana and 'ciku', we just mashed it up. I initially steamed the papaya, but it became too mushy and sweet.