When I was younger and even more recently, I used to download and read copyrighted inappropriate novels. I now want to make teshuva, but I don’t think it’s a good idea to buy the books from the authors due to their content. I can’t remember all of the books, but I do remember a good number of them. They weren’t all inappropriate — some were simple secular books. However, I don’t recall whether some of them were read using a subscription reading program, which would mean they were paid for. What should I do? Can I get a subscription reading program for a month and check off the books that are included in it as paid for? And then do something about the rest? I’m also a bit embarrassed to tell my husband that I need to spend possibly a lot of money on this.

That's a good suggestion, to take out a subscription and check off the books which you read, that way you return the debt owed to the publishers and authors. Aside from that, regarding the books which you don't remember, in such a case, the proper thing to do is donate however much you can to a Jewish communal or national (Israeli) need and that way the masses can benefit, which is a way to sort of compensate for owing money to masses who cannot be tracked down.