In more progressive organizations that have built a climate of trust, employees provide 360 feedback directly to each other. The manager does not function as a filter or go-between to prevent employees from sharing their feedback directly with each other.
No matter how you collect and share the 360 feedback, you must always take care that the feedback is as descriptive as possible so that the employee has something tangible to improve. When sharing is open, make sure also that you solicit frequent employee feedback about how the process is working and affecting employees.
In any case, how you introduce, monitor, and evaluate the effectiveness of the 360 review process is critical to its success or failure. You will want to take a look at sample questions for 360 reviews.