QGIS 3.0 has a powerful new way to create automated mapbook products called reports. If you are familiar with map atlas’s in QGIS 3 or data driven pages in ArcGIS you will be somewhat familiar with the basic premise.
QGIS reports go to en entire new level. They allow you to include header and footer pages and static map layouts with your map atlas’s. This is handy to include cover pages, overview maps, common legend pages etc which can certainly save a lot of time inserting and ordering pages when it is time to create a final document. This is especially true if that document gets updated frequently.
But the real power of QGIS reports is to include hierarchical nested sections. For instance you could have city maps, nested within township maps, nested within county maps, nested within state maps.
The reports feature is new and under active development. The developers have mentioned that a lot of new functionality will be included with the next release of QGIS 3. I have no information as to what thse features will be at this time but I am very excited to find out. High on my personal wishlist would be the ability to tie summary tables and charts to the data being shown in the map.
Until then I highly recommend that you explore what is currently available. This video will get you started.
This video is also one lecture out of 76 in my course on QGIS 3.0 for GIS Professionals. This course has over 11 hours of video and is available now on Udemy.com for $20 You can read more about it here.