Properly setting up a SharePoint blog can be confusing, especially the permissions. Below is a repost from the Graham Alltoft SP blog.
Permissions on SharePoint 2010 blog posts
When setting up a SharePoint 2010 blog posts on an intranet site, it can be easy to get frustrated around the setting up of permissions. You may want some users to be able to create and edit blog posts, whilst everyone else can contribute their comments to a blog post but not create their own. Pretty typical setup.
You can set your bloggers to have Contribute permissions at the root of the blog site which will allow them to create and edit blog posts. Nice and easy. However, the next out of the box permission set is ‘read only’. Giving your remaining users this permission will allow them to read blog posts only, and not allow them to add comments. There is nothing in-between at this stage.
To ensure your read only users can comment on blogs only, you need to navigate to the list where the blogs are stored, at http://YourSite.com/YourBlog/Lists/Comments/AllComments.aspx. So…
- Navigate to the all comments list (sample link above)
- On the ribbon click the ‘list’ tab
- On the ribbon click the ‘list permissions’ button
- Click the ‘stop inheriting permissions’ button on the ribbon
- Click the ‘Grant permissions’ button on the ribbon
- Whatever group or individual you want to grant permission to add their comments to blog posts, give them ‘contributor’ rights
It is also best to ensure a single user can only edit his / her own comments. To do this…
- Navigate to the all comments list (link above)
- Click the ‘list’ tab on the ribbon menu
- Click the ‘list settings’ button on the ribbon
- Click ‘Advanced settings’ under the General Settings heading
- Change the ‘item-level permissions’ section, selecting the ‘Create items and edit items that were created by the user’ option
- Click ok and test
The result of this should be that only permitted users can create blog posts, everyone else can only comment on them, and only edit their own posts. There is a plethora of other options, so have a play about to customise it to your own needs.