I'm writing a web application that will allow people to create accounts, edit stuff, send stuff to people, &c. I plan on recording things like when things were created and sent and stuff.
Is there a list of usage information that one should collect in a web application? I'd like to see whether I'm missing something.
Also, is there a list of usage information that I shouldn't collect (Like maybe information that people find private)?
EDIT: I was thinking about information that is collected automatically (like timestamps and ip addresses) rather than information that is entered manually.