I am a fee-only financial planner. I want you to know that ahead of time so that you know that I am not unbiased.
Anyway, a person should hire a planner if they don't want to do or learn these things on their own. Also, there is the accountability factor. It seems most people will act on a plan that they paid for when they won't for something they came up with themselves.
If you do hire a planner, I recommend (again, I'm biased here) a fee-only planner. There are fee-only planners out there that can do as little or as much planning as you need. Check out the Garrett Planning Network (
http://www.GarrettPlanningNetwork.com).
I hope this helps.
JLP