Writing a log file

[repuust]

I am trying to do something which I assume is simple, but can't find any tutorial or help on it. All I want to do is have some sort of log file that is generated on install. It implies that if I use DetailPrint messages and then use SetDetailsPrint both, I would get some sort of log file.

1) Is this correct?
2) Where is this log file?
3) Can I call the file something else and/or change the path?