A short list, grouped from easiest to most demanding. Start wherever you are.
Start here
Thinking about long lives.
The 100-Year Life
BeginnerLynda Gratton and Andrew Scott
How longer lives change education, work and retirement, and why careers may need more stages.
Social Security
How the American system works in practice.
Get What's Yours: The Secrets to Maxing Out Your Social Security
IntermediateLaurence Kotlikoff, Philip Moeller and Paul Solman
A practical guide to claiming decisions, including why waiting can pay.
Go deeper
The official numbers.
The Annual Report of the Social Security Trustees
AdvancedSocial Security Board of Trustees
The yearly report that projects when the trust fund runs short. The source behind dates like 2032.