"We occasionally get asked about how companies should allow their staff to blog and what is acceptable behaviour online. Years ago, Simon Harris of Sun Microsystems guided me towards their website where the company allowed any staff member to have a blog."
Read the full article to access links to Sun's blog and IBM's social media policies for staff.
Why recreate the wheel. These are good references and starting points if you're looking to create or tweak your own policies.
For even more examples have a look at All Things IC resource 300 social media policies. Make it easy for staff to read and adhere to policies by keeping them short and sweet.