Recommendations on SharePoint site permission model

I have a SharePoint site which contains a root site and site collection in it. Now there are some sites that inherits permissions from their parent site and some site has their own permission module. Now a user from owner group of root site browses site collection but there are few site which doesn't allow user to view the content of it.

Now what I want is general recommendation on when creating a new site in SharePoint what is best p开发者_如何学运维ossible approach to set site permission.

In what case we can inherits permissions from parent site..? In what case we can we us unique permission for a site..? If a site has unique permission set then is it possible to creat a group at root level which has access to all site collection irrespective of site permission model?

I want a general recommendation based on above scenario.

Any help will be appriciable.

Thanks Sachin

In many cases we can't inherit permission in all subsites/ lists. And if we are not inheriting it we can't create a new group which have same permission in all sites/lists. But we can overcome it with the following way.

Create some common permission group with deferent permission level. And create site with inheriting permission and remove user groups from new sites except the common group.

If a new user wants access in all sites/ list you can add this user in appropriate common group.