Blueberry Blonde recipe help

So my brew partner and I have made a blonde ale and currently have it in its first fermentation. We would like to make it a blueberry style blonde and are seeking advice. We know that the blueberry gets added to the carboy for secondary fermentation. Reading different recipes we are puzzled as to what to do. People say puree frozen blueberries, boil em, add jam, etc. For those that have done something of the sorts in the past what do you find the best way to go about adding fruit flavoring? Do you add it to the carboy before syphoning? And how much do you use for a 5 gallon batch?

Any help is welcomed and appreciated

Thanks

AHB