There are several great tools out there for editing PDF’s and annotating them. Many Mac users don’t know that a lot of that functionality is already built into OSX.
To get started right click (Control + Click) on the file (PDF,JPEG,PNG,etc.) that you want to annotate.
When Preview opens you will notice a few items on the top toolbar. Click on the “Show Edit Toolbar” button.
This will open a toolbar with several different tools.
Here is an example of what these tools do:
I utilize Preview quite a bit to enter text into forms, to highlight and to even sign documents.
If you have any other tips or questions please feel free to comment below or shoot me an email. firstname.lastname@example.org