What to read about the organization of program code?

Question

C++ / C#

Good afternoon!
Tell me what good to read about the organization of code in medium-sized applications. I'm writing a toy in AS3, and the more I add to the game, the more complex the architecture and the mess I get in my classes. When I first started writing, I rewrote the entire code 4 times, because the architecture did not suit, everything is like from the fifth point. Now it has somehow become tolerable, but still, I feel that there is no harmony. I won’t rewrite it already, there’s a lot of work, but at the end of the year I plan to start mastering Qt, respectively, to start with C / C ++. So I would like experienced people to suggest what to read for the normal organization of the code, tk. I plan to make a small application and there I will have to work with the server, and the database, and create an auto-update of the application, here, accordingly, I need to write adequate code that I could support

Answer 1

Steve McConnell "Perfect Code"