Queues allow groups of users to manage a shared workload more effectively. A queue is a location where records can be routed to await processing by a group member. The records remain in the queue until a user accepts them for processing or they are transferred to another queue.
You can specify the set of objects that are supported by each queue, as well as the set of users that are allowed to retrieve records from the queue.
To Setup Queue follow the below steps,
Step 1 : From Setup, enter Queues in the Quick Find box, then select Queues
Step 2 : Click New
Step 3 : Enter a label and queue name. The label is the name of the list view that users work from
Step 4 : Choose whom to notify when new records are added to the queue
Step 5 : If your org uses divisions, select the queue’s default division. Cases inherit the division of the contact they’re related to, but when a case doesn’t have a contact, it’s assigned to the default global division.
Step 6 : Add which objects to include in the queue.
Step 7 : Add queue members. Members can be individuals, roles, public groups, territories, connections, or partner users.Depending on your sharing settings, only queue members and users above them in the role hierarchy can take ownership of records in the queue.
Step 8 : Save the queue.
Step 9 : If you want, set up assignment rules for your lead or case queues so that records that meet certain criteria are automatically added to a queue.
This blog information is very useful to learn about queue setup in salesforce.