Treat a windfall like a PowerBall win:
Tell no one, not even family. If you must talk, do so with one who is already in the know.
Don’t run out & buy new “stuff. People notice.
Get an unpublished number and give it out very sparingly.
Get a tax accountant you can trust to make sure the IRS is satisfied (Certified Opinion is something to look into) and pursue asset protection.
Move slowly (e.g. change of car, address, furnishings). People notice.
If you are going to stay where you are look into fire/burglar protection. They have all sorts of extras nowadays and you do not have to advertise them or for them.
Get identity theft protection. There are several companies out there – check them out, ask for preferences from those who have it.
Reduce and remove debt. Stay on top of your credit report. I don’t believe in paying these outfits to check regularly. An identity theft protection company should be able to tell you if someone accesses it or affects it
– Life Lock. Remember – once out, your phone & mail will be swamped with requests for money and “offers”. 
Friends and relatives you never knew you had will show up at your door with a “problem”.
You will get swamped with charity “membership renewals”, calendars, cards, tokens, key rings, etc. all with donations in mind. Giving comes from the heart. Make sure taxes are paid and be aware of future tax liabilities incurred from your investments. For information on what to go with, invest with, work with, be diligent. Check it out. Ask those who also have wealth.
Never, ever make a major decision on the spot. That boat, car, house, etc. is not going to go away while you sleep on the decision.