This book covers all the topics, but some more examples and point of views on the same subjects can give you even more confidence.
I suggest you to jump to Trailhead and complete the Advanced Administrator Trailmix at https://trailhead.salesforce.com/en/users/strailhead/trailmixes/prepare-for-your-salesforce-advanced-administrator-credential, which covers a bunch of the topics as well. This is not a comprehensive guide (at least as of Winter '20), so you need to search online for further guides and training (chances are you chose this book to deep dive into certification topics).
I suggest reviewing the Administrator certification topics as well to refresh your knowledge of administration stuff (a dedicated Trailmix is at https://trailhead.salesforce.com/en/users/strailhead/trailmixes/prepare-for-your-salesforce-administrator-credential, a certification that is a prerequisite for the Advanced Administrator certification).
Besides the Trailmixes, a good way to test your skills is to go through the Trailhead Superbadges (located at https://trailhead.salesforce.com/superbadges), which are intended for administrative staff, such as the following:
- Lightning Experience Specialists
- Lightning Experience Rollout Specialists
- Process Automation Specialists
- App Customization Specialists
- Security Specialists
- Business Administration Specialists
- Lightning Experience Reports and Dashboards Specialists
- Service Cloud Specialists
This list may vary month after month when the Trailhead team releases new content; follow Trailhead on Twitter at @trailhead to hear about the new content.
Throughout this book, we have given you plenty of references, which I politely suggest that you look at to get a comprehensive view of all the main topics.
Remember that Google is your friend: search for Salesforce Advanced Administrator Certification and you'll find plenty of blogs and online courses to read and use to progress.
The Trailhead Academy provides the following classes (virtual and on site). You can find them at https://trailhead.salesforce.com/en/academy:
- Administration Essentials for Experienced Admins (ADM 211) (https://trailhead.salesforce.com/en/academy/classes/adm211-administration-essentials-for-experienced-admins)
- Certification Preparation for Advanced Administrator (CRT 211) (https://trailhead.salesforce.com/en/academy/classes/crt211-certification-preparation-for-advanced-administrator)
Another amazing place to increase your skills to the maximum levels is the Trailblazer Community (https://success.salesforce.com), where you have a few options:
- Local community groups (https://trailblazercommunitygroups.com): Find local meetups and join (or even organize) training sessions with your local pals.
- Advanced Certification Study groups (https://success.salesforce.com/_ui/core/chatter/groups/GroupProfilePage?g=0F93A00000020CqSAI): Virtually join other trailblazers and exchange knowledge with them.
- Training groups (https://success.salesforce.com/featuredGroups?filter=a0L3000000Rq7K5EAJ): Official Salesforce training groups.
Finally, you can even join Salesforce's Certification Days at https://pub.s7.exacttarget.com/ryqkengawga. These webinars are free for all, and will help you get an insight into the key topics for various certifications, and you can even get a discount for your next exam.