I just bumped into a great list of free writing prompts that was produced in relationship to the New York Times. Many of them are great for Memoir Writers, and all would be wonderful ways to launch a blog post. I believe that the prompts were intended for teenagers, but they are equally good for adults who are writing about they youth. I thought that you might like to check them out Here
Here are a few examples:
What Was Your Most Favorite Childhood Possession?
What Were Your Favorite Shows & Characters?
What Were Your Favorite Picture Books?
What Things Did You Create As A Kid?
What Places Do You Remember Fondly As A Kid?
What Objects Tell the Story of Your Life?