Hi Loobylou,
Not sure how much help I can be, as I've been asking the same questions! Apparently you only need to give water if baby is constipated or dehydrated (or risk of dehydration, i.e. hot weather), I have given E a oz of water a couple of times in the recent hot weather, usually when she is making her normal hunger motions, but I know she can't possibly be - she's taken the water and it seems to settle her, so hopefully it's what she wanted!
I'm the same as you with the sun screen, I try to keep E in the shade as much as possible, but I'm sure you can still catch the sun even in the shade and there are always those few minutes, esp. when out in her pram that she is in the sun. I have bought a little bottle of sun cream to keep in my nappy bag, just in case, but haven't actually used it yet.
Be interested to hear what others are doing
E x
Esme Rose born 2nd February 2011