You can choose several contacts to be assigned to one or more campaigns. 

Go to the contact list and select the batch tab and choose the batch campaign option.

Then, you select the campaign you want to add the contacts to. You can see the campaign summary as well as all the actions to be sent in the campaign preview, you can also select the action you want to start the campaign in.
To send the campaign you can send it right away or you can schedule it for the future.

If you want to track the campaign information for the batch campaign you sent, you can do so in the Campaign Dashboard.