Standard answer is the Thrawn Trilogy starting with Heir to the Empire. Although Truce at Bakura starts minutes after ROTJ ends. I’d start with the trilogy and move from there as you please. There are books and comics before prequels, during prequels, OT timeframe, and post ROTJ
I’m still happy reading the EU. Disney made me not care about new Star Wars projects
Any recommendations? I've always been interested in it
Standard answer is the Thrawn Trilogy starting with Heir to the Empire. Although Truce at Bakura starts minutes after ROTJ ends. I’d start with the trilogy and move from there as you please. There are books and comics before prequels, during prequels, OT timeframe, and post ROTJ