Childrens portraits
 

I am an amateur, I have been asked to do some portraits of some children one is 4yrs & the other 10 weeks. the problem is I don't know how to place the kids together to get some good shots, I have borrowed some studio lights & backdrops, but I don't know what position to place the kids in together, does anyone know of a link where I can get some good ideas from or some pictures of some poses

There are plenty of websites out there so a quick look through some should give you plenty of ideas.
Shooting as it happens is ok but I've started to write down the shots I want to do then if the child needs a break you know where to restart from. Get the parents to bring some toys along to keep the kids amused (plus you maybe able to use them in the shots). Changes of clothes for the kids will add a bit more variety.