Probably the quickest and easiest way I can think of is to get on craigslist and looking up all the garage sales / estate sales in the area(s) you're interested in. That way you have a address so you can start doing your homework and you also have their contact info.
Grab your local newspaper. Look under classifieds. Go to legal notices. The heading should be "Notice of Probate" "Notice of Heirship" "Notice of Administrative Probate", etc.
Here in CA, probate petitions are titled "Notice of Petition to Administer Estate" in the local adjudication paper..