In my experience, you do not need to consult every resource and every practice test out there; that will only bog you down. Below are the resources I used to prepare for the HT. They are the only resources I used before passing the HT on the first try.
Books & websites
* Histotechnology: A Self-Instructional Text, 5th edition, by Carson and Cappellano -- Focus on this. If you don't read anything else, read this. Inhale it. Memorize it. Memorize the pictures. Memorize the captions beneath the pictures. Stamp it into your brain. You may have scrolled through forums and read of people who said you must memorize the book, back to front, and re-read everything ten billion times. Yes, what they say is true. Please read the textbook, and read it carefully.
* Leica's educational hub: https://www.leicabiosystems.com/knowledge-pathway/
- especially these pages:
- https://www.leicabiosystems.com/knowledge-pathway/steps-to-better-microtomy-flotation-section-drying/
- https://www.leicabiosystems.com/knowledge-pathway/an-introduction-to-decalcification/
- https://www.leicabiosystems.com/knowledge-pathway/staining/page-0/
* NSH's blog:
- Alcian blue
- Silver stains
Practice tests
* Histotechnology: A Self-Assessment Workbook, 5th edition -- This is the companion to the textbook, containing practice questions for every chapter. Great way to test yourself after finishing a chapter. The answer key also provides short explanations, so that can be an additional resource.
* BOC Study Guide, 3rd edition -- I got the physical book, and my school provided the online version. Both versions are exactly the same, with the same questions. You can go with either one. I got the physical book as well because I wanted something to flip through and read without having to stare at the screen all the time (the answer key also provided short explanations). The online version, though, was great for simulating the actual exam. Get the version that works best for you.
* NSH + LabCE Histology Exam Simulator -- This is an online-only exam simulator. It is very different from the BOC simulator (which had easier, more straightforward questions). The LabCE simulator had more obscure questions, and questions that made you dig deep into your knowledge bank. I highly recommend getting this too, if you can. It is a great complement to the BOC Study Guide, giving you a well-rounded practice experience.