Evolve/Reach HESI Admission Assessment Exam Review from Mosby is the only specific HESI book that I'm aware of. Mine is 2nd ed., ISBN 9781416056355
But the McGraw Hill general nursing preentrance exam study guide is pretty similar.
There are some posts on here where people tell what their HESI preentrance exam was like. Some sections tracked the study guide pretty well, and others didn't.
HESI exam is specific sections and student has a set number of hours to complete it but in any order. The schools can customize the HESI somewhat, and they can include test questions that are not included in the score. I guess that's like something that can be used to screen applicants, like to see if some are more educated than others. I dunno.
Math is like GED Math Review book math.
Reading, Vocabulary, Grammar are all just like all the other study guides.
Biology is general biology like a Cliff's Notes biology book has.
Chemistry, you'd probably want to take a look at.
Physics was pretty lightweight on the test question material, not as difficult as what was covered in the HESI book.
A&P had a fair amount of questions but they weren't too "exotic." More like basic structures and such. I had more difficulty with the A&P than any other part, but most of the other stuff I'd actually used for years in real life, too. A&P, I just took the class for a nursing prereq and I had a little trouble recalling some of it.
I took the HESI at two different schools. One used the online Elsevier/evolve/Reach site and it was a totally online test. It was scored immediately. The other school had a more customized version of it on their local Intranet and as I recall, we had to wait a few days for test results to be available and posted.