Most publications will include content that was created by others, known as third party content. Using third party content with or without seeking Permission requires careful consideration.
Many copyright materials have terms and conditions which permit a range of further uses. Also, Australian Copyright Law allows use of third party content, with or without seeking Permission, provided certain conditions are met (See Fair Dealing).
Some materials, such as Open Educational Resources (OER), may allow you to use some or all of their content without needing permission, but you will need to check the terms and conditions attached to each OER to determine what is covered.
Some materials may have specific terms and conditions which mean they cannot be used for your purpose. In such cases you should see if other material is available or create your own adaptation or version of the material.
In some cases it may be necessary to seek permission from the copyright owner.
It is important to use the appropriate amounts of any material created by others, including for quotes, extracts, diagrams, images, maps, sound, video, etc., and correctly cite these, before the work is shared with others and considered for publication.