We currently have 9 questions with the tag [tag:probate].  

Wills are an especially rich source of names, which is a great way to jumpstart cluster or FAN (friends, associates, neighbors) research.  Even something as simple as an entry in the National Probate Index can provide important clues. 

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This answer became Weekly Topic Challenge #6: https://genealogy.meta.stackexchange.com/questions/1926/learning-more-from-probate-records-and-wills