David Brins's Uplift series is pretty good
1. Sundiver
2. Star tide Rising
3. The uplift War
Mankind ventures out in the universe and meets alien races none of whom eveidoed to sentences naturally , in fact they were uplifted to that star by older races and those races the same thing. In fact mankind is the only know race in the galaxy to ve evolved to sensitive nataully and everyone is bailey jealous us for that reason . Mankind has upkifed other species to sneticnaes an awareness . Chimps and Dolphins and they are some the most interesting character in this series. And also out civilization got into space with the benefit of anince left over tech and knonesg bu the unknown myerisous progenitor race that began the whole uplisiging of life in th galaxy.. This series is a blast !
Also
Between the Strokes of Midnight by Charles Sheffield
Traders World by Charles Sheffield.
The Star Crossed by Ben Bova comic science fiction novel Its a thinly disguised fictionalization of what happened when Harlan Ellison when he tried to do the series called
The Star Lost in the early 1970's This book is appositive joy to read.
Way Station by Clifford Simak. one of the greats
Doomstar by Edmond Hamilton
The Reef of Earth by R A Lafferty
Berserker by Fred Saberhagen
The Veils of Azlaroc by Fred Saberhagen
Empire of the East by Fred Sabergagen
The Crossroads of Time by Andre Norton
Daybreak 2250 AD by Andre Norton