Thanks, eldestgirl, that's a useful tip re carrots. I just read today a tip re basil: they prefer to be in a clay pot, which loses moisture faster than a plastic one, and ideally you should water them at midday, so that the water evaporates/is used before evening falls. They don't like sitting in wet soil.
Gski, running to seed means the plant goes through its stages of development too quickly and flowers then produces seeds before you can make use of the leaves. It's like they become adolescents overnight - in fact pregnant teenagers You're supposed to pick the leaves a few at a time.
Don't know about ideal height of raised beds, but lots of people make them the right height for easy picking. If your kids are a suitable age, then you could make the beds a good height for the kids to pick the veg?