Sharepoint 2013 setup group permissions

Question

In my SharePoint 2013 test sharepoint site, I would like to know how the users should normally have access to the test sharepoint site. Would the user sign as themselves individually or would they sign on with a group id? Can you tell me and/or point me
to a url that will show how to setup group permissions and how the users should login?

Answer 1

There are two suggested ways to assign permissions on SharePoint sites:
    Using SharePoint Groups  
    Using Active Directory Groups
Note: A site can be set up to either inherit permissions from the parent site, or to allow unique permissions to be set for the site. If the site is set up to inherit permissions from the parent site, you will have to Add Users or Active Directory Groups
to pre-existing SharePoint groups in the parent site.
Using SharePoint groups:
Click on “People and Groups”
Click on “New” from the drop-down menu
Select “New Group” Under “Choose the permission level group members get on this site:… ”
Select “Contribute” and click OK.
Click on “People and Groups”
Click “New”, from the drop-down menu
select “Add Users” Type in the netID(s) you wish to add
Click on “Check Names” (the netID(s) should now be underlined)
Under “Give permission”, select the group you just created and click OK.
Note: If site owners want their site to show up automatically in users' "My Links" in "My Site" then those users must be part of a SharePoint group and that group must be defined as the "Members of this Site" group.
Using Active Directory Groups:
Click on “Peoples and Groups”
Click on “New” from the drop-down menu
select “Add Users” Type in the name of the Active Directory group you wish to add
Click on Check Names (the group name should now be underlined)
Under Give Users permissions directly, select “Contribute” &click ok.
Note: You can specify multiple netID(s) or AD groups by separating the names with a semi-colon(;).
Below are list of permissions you can use for the site.. 
Permission Level
Description
Full Control
This permission level contains all permissions.      Assigned to the
Site name Owners SharePoint group, by default. This      permission level cannot be customized or deleted.
Design
Can create lists and document libraries, edit      pages and apply themes, borders, and style sheets in the Web site. Not assigned      to any SharePoint group, by default.
Contribute
Can add, edit, and delete items in existing      lists and document libraries. Assigned to the
Site name Members SharePoint      group, by default.
Read
Read-only access to the Web site. Users and      SharePoint groups with this permission level can view items and pages, open      items, and documents. Assigned to the
Site name Visitors SharePoint      group, by default.
Limited Access
The Limited Access permission level is designed      to be combined with fine-grained permissions to give users access to a specific      list, document library, item, or document,
without giving them access to      the entire site. However, to access a list or library, for example, a user      must have permission to open the parent Web site and read shared data such     
as the theme and navigation bars of the Web site. The Limited Access permission      level cannot be customized or deleted.      
NOTE You cannot assign this permission level to users or SharePoint      groups. Instead, Windows SharePoint Services 3.0 automatically assigns this      permission level to users and SharePoint
groups when you grant them access      to an object on your site that requires that they have access to a higher      level object on which they do not have permissions. For example, if you grant     
users access to an item in a list and they do not have access to the list      itself, Windows SharePoint Services 3.0 automatically grants them Limited      Access on the list, and also the site, if needed.