The book is short and straight to the point, if you read it carefully you will do fine. If a college is using this book without properly preparing students it is the colleges fault. I also think many of the students in Comp Sci programs are not actually cut out for computer science. Computer Science concepts are very hard, and you have to love everything about computer science, actually be a real geek to excel. I own at least 200 books on all subjects of computer science, including 16 books on Perl alone. From my experience no one book covers all concepts in detail.
This book will show you how scripts work with html forms and process information on the server, that is all it is meant to do, if you want to know Perl in dept, then you may want the Perl by Example book, which I am reading along with this book. If you have no programming experience, then you may want to learn the basics of programming before attempting this book, it will not explain how to program.
Many people have a very hard time with programming classes, and other Computer Science, IT concepts. I love all of it and blast right through these books, my main goal is to master these concepts, I currently have a 4.0gpa and go entirely online, which is really hard since you have no one to directly ask questions. But I have been teaching my self for several years, I started while working on a boring degree in Accounting, which did no good for getting me a job, even though I graduated with a 4.0gpa.
If you are not obsessed with computer science concepts maybe you should consider a different field of study and work, many people start these programs and soon drop out that is why there is a shortage of people entering the field, there is absolutely nothing easy about it. I find it to be fascinating and my brain will not stop thinking and wanting to know more, to me all of it is fun to learn, no matter how hard or complicated.