Log File Management

I’m new to warcraft logs and I have a few questions about how to manage my log files, both locally and on the web.

  1. Should I retain my log files locally after uploading? Should archive files be kept?
  2. How much space is available for personal log files/guild log files on the web and how do I monitor it?
  3. Do uploaded log files expire?
  4. Are there any general guidelines?