I see this post dates a little but thought I would share my views on the subject with you.
First of all there is, as you say no ‘best practice’ with one exception I think. The parent should always speak to their child in their ‘heart’ language. For me this is English and for their father it is French. From day one I have spoken English to my three daughters and My ex-husband always speaks French. I cringe when I hear people speaking (bad) French to their children when they are obviously not French.
My eldest, born in London, spent 2 years in an Italian day nursery in Luxemburg where the staff spoke Italian , many of the children spoke French or German and her best playmate was Norwegian!
At 2 years old she could communicate with all of them. She was 6 when we came to live here and is now at Uni in Montpelier.
The middle one, born in Luxemburg started in petite section of maternelle and is passing her ‘Bac’ this year.
The youngest was born here and although I spoke to her always in English, she answered me in French for years. However whenever we were with English speaking friends or family she would start chatting away in perfect English!
They tended to play in English and ‘work’ in French but now they do a little of each!
As for reading, I have always read to my children when they were little and their bed-time stories were normally in French from their Father. They had a selection of books and videos/dvd in both languages but I do try to ensure that they watch things in VO, whatever that may be.
All three speak both English and French with no accent, so you see, children can work it out for themselves, they are all different and it is just up to us to be consistent in all things, not just language and guide them along the path.
Enjoy your family!