There were not a lot of novels that covered the time just before A New Hope or just after The Empire Strikes Back. Partially because the comics covered what was going on between films, and until the Prequels, the era before A New Hope was mostly avoided as the only character viable were Han Solo (two trilogies by different authors decades apart) and Lando Calrissian (one trilogy). No one was going to seriously do a novel on Obi-wan Kenobi at that point, and the Droids were covered via a cartoon series.
Shadows of the Empire was I think the only novel set between The ESB and Return of the Jedi. There were also the short story collection books "Tales from the Eisley Cantina", Tale of the Bounty Hunters" and "Tales from Jabba's Palace" which cover various background character over their lives, before and sometime after the events of the films.
After the Prequel Trilogy, the was some Kenobi novels that take place between Revenge of the Sith and A New Hope, but I think those were closer to ROTS. There might have been some later novels that were set in this time period prior to Disney's take-over, but most that I am aware of that were good took place closer to ROTS, or were done after Disney took over.