I have a game that I have been writing as a hobby for a number of years. I have very sparse logging, just some simple output when something goes really wrong. It's about 25,000 lines of code.

I just released a first beta, and I'm realizing it is going to be a nightmare to deal with bug reports without good logs. Whenever something goes wrong on my test machine, I have the luxury of looking at the code, adding print statements. Obviously, that's not available once its released in the wild.

1. Do you think it is advisable to try to add logging to this program now? Or do you think that I'm too far along to try to fix this problem?
2. Do you have any recommendations on how to go about doing it? I honestly don't know where to start.
3. Do you have a recommendation for a logging system for Java?
4. Do you have any good articles / best practices recommendations on what to log and how to log it?

Thanks! Any and all information is greatly appreciated.