Nodeaccess

Nodeaccess is a Drupal access control module which provides view, edit and delete access to nodes. Users with the 'grant node permissions' permission will have a grant tab on node pages which allows them to grant access to that node by user or role. Administrators can set default access controls per content type, and also define which roles are available to grant permissions to on the node grants tab.

The upshot is, this module allows you to do things like 'node 123 can be viewed by authenticated users and edited by admin users and joeuser'. As an added bonus, update and delete permissions are separated, so you can make sure users with edit permissions cannot accidentally delete pages.

7.x version
The previous maintainer (chadcf) had released a dev version of nodeaccess for D7. Over the following months a number of bugs/issues were reported and as of May 7th, 2013, all bug reports in the issue queue have been addressed (where possible) and with that, version 7.x-1.0 has been released as a stable/recommended release for Drupal 7.

Domain access compatibility
If you are utilizing the Domain Access module and wish to use it in conjunction with Nodeaccess, you should also install Domain Access Bridge in order for it to work properly. Otherwise, you may run into a scenario where a satisfaction of Domain Access OR Nodeaccess conditions result in special node permissions (instead of requiring them both).