Decide Which Features Make Sense for Your Organization
As you consider how best to take advantage of the social computing features in SharePoint, keep in mind that using these features is optional. For the most part, you can enable selected features without enabling all of them. You can choose to enable the features over time, after you've figured out your governance model and developed messages communicating how these features are both applicable and beneficial in your environment.
For example, before deciding to enable users to add ratings to content repositories, you should make sure that everyone understands what they're rating and what the rating scale means. The ratings feature allows users to rate content and then exposes the ratings as metadata that can be sorted, filtered, and queried. Adding ratings to content theoretically makes it easier for users to find high-quality content. In practice, if you choose to enable this feature, you'll need to be sure that users understand what should be rated and what criteria should be used to assign a rating.
You need to define the context for ratings clearly: Do you want users to rate how much they like the content (which might be appropriate when you're asking users to help choose among several alternatives), or do you want users to rate the value of the content for a specific purpose? Be sure that your document library description tells users what ratings mean in the context of your library, if you choose to enable this feature.
Another area where you need to decide what makes sense is in the content that you ask users to place in their profile. Is it okay to publish birthdates? In some companies, it's okay as long as the feature is optional. In others, sharing birthdates (even without the year) is not allowed.