Drupal offers a wide selection of node access modules.
Many (but not all) of these offer role based access control.
While still only in beta for D7, Content Access is a module I personally use for role based node access control. I regard it as stable for role based access control. However do not use it for lower resolution (user based) access control, as this mode is not yet stable.
This module allows you to manage permissions for content types by role and author. It allows you to specifiy custom view, edit and delete permissions for each content type. Optionally you can enable per content access settings, so you can customize the access for each content node.
One of the advantages by this module is that it is fairly straightforward to control access to individual nodes by role.