Profiles can contain as much or as little information as the user decides; there are entry fields for name,
nickname, occupation, location, "about me" and a photo. Users will also be allowed to create multiple links for their site. For example, if you add or edit content on Google Maps, someone else can
click through to your profile.
While you control what information you enter about yourself, there doesn't seem to be any "fine-grained control" over how much information you share. Your contacts will be able to see your full profile, while others will see basic name, occupation, location information and links. Thus far, Google has released little information about the service.