I suggest you join the WA Waterfowl Association:
Check out the "work party" thread by Skeeter; the Whatcom Chapter of WWA hosts this FREE event every year with a GREAT FREE BBQ. Not only will you be exposed to some great public hunting areas in Whatcom County, but you will also meet some great people; who can give you possible private / lease info. Also, this event is very "Kid Friendly". You do not have to be a member to attend.
Also, check out the WDFW website:
Links to "Hunting" and "Regional Offices" can be very helpful.