A queue is a collection of posts that you can manage by setting how many posts and at what times the posts are published. As long as you have posts in your queue, it will keep publishing posts daily so you don’t have to do manually. I’m sure you already know this but you can access your queue by going to your blogroll and it’s under your ‘drafts’ or you can simply go to http://www.tumblr.com/blog/yourusername/queue. You can also arrange them in the manner in which you would like them to be published. I hope that helped!