Yep, it's important to work out what you need and then ask for the appropriate help. With a young family it may be that you want to have a couple of people on standby for childcare (if there's school or kindy involved, make sure they know and that you have the appropriate friends/family added as emergency pickup people).
I had some lovely friends who brought over a few meals but the biggest things were providing somewhere for my kids to go after school when treatment ran late, and a friend who drove miles across town to pick up my daughter and take her to a school sports competition during the day while I was having treatment.