I'd start with why you're unhappy with your current schools -- what are they doing (or not doing) that bothers you? Is it specific to that school, or a systemic issue that might also happen in your new location?
And, of course, note the things that are going well at your kids's schools; things you'd like to keep if possible.
Those things together may help you get a list of questions to ask. Unfortunately, school decisions are so personal that it's hard to just make a list of questions someone else may want to ask.
DC1 -- 2005 DD -- 2009 DS -- 2011