I started today! LO is 6 months in just under a week. We are hoping to go down the BLW route so LO had toast for breakfast and some tomato flavoured rice cakes as a snack this afternoon. Not much of it got eaten though! Not that it matters as the first month she'll probably just be learning!
I felt LO was definatley not ready any earlier than this and like someone else said, if you wait till 6 months, you can skip the puree part, go straight to whole food or mashed/chopped lumpy food and they can have pretty much anything (barring too salty, whole nuts, honey and runny eggs!)
Good luck when you get to 6months!! xx