I first read this book my sophomore year in high school when I started wolfing down every bit of sci-fi I could get my grubby adolescent hands on.
I remember I loved the Heechee Saga, but in the way of old memories (and having read all of the available books at once), things got fuzzy so I could only "sorta kinda" tell you what the story arc is about.
Delightfully, the suck fairy has not found her evil little ways into this book. A sci-fi classic, this book remains relevant and doesn't feel dated the way a lot of older books can.
It's 99% character development. The world in the future isn't a pretty place, with too many people, where life is cheap, but living is expensive. Humanity has stumbled across the artifacts of an advanced space faring species, and is trying to discover more about it, but that's only the backdrop of the book.
The book is about Robinette Broadhead, a serf on the planet Earth who manages to make it to Gateway to try his hand at being a prospector. The story is told in alternating chapters, either currently while living his prospectors' life and as flashbacks as he discusses life with his "shrink". These chapters mesh remarkably well and the means of advancing the story this way is wonderful.
This book is a standalone (not intending to be the start to a series) and is one of my favorite reads of all time.