Avoid publishing stubs: Users don't like seeing "empty" pages, so avoid placeholders where possible. For example, don't publish pages for which you don't yet have real content. If you do create placeholder pages, use the noindex meta tag to block these pages from being indexed.
Some good advice about how to handle duplicate content on your own site:
1. Recognize duplicate content on your website.
2. Determine your preferred URLs.
3. Be consistent on your website.
4. Apply 301 permanent redirects where necessary and possible.
5. Implement the rel=canonical; link element on your pages where you can.
6. Use the URL parameter handling tool in Google Webmaster Tools where possible.