A.B.
Hi, congratulations! July is a great time of year to move here.
Usually big companies like Virginia Mason have relocation specialists, especially if your husband is being assigned for a year. I'd ask your husband to ask his HR contact who you should talk to about local area schools and housing near his work. They'd probably have great contacts and recommendations for you since most big companies here are interested in the whole family - not just the employee - being happy.
Also, when you get here, a great resource to sign up for is Red Tricycle http://redtri.com/seattle-kids/
they have an email newsletter and are always promoting free things to do with the kids, so it's a great resource for a family on a budget!