WHAT TO PICK?
You have to make sure that whatever style of book you choose, it fits your theme. First and foremost, theme is the overall important factor. If you have a good theme that you like, the style of book can enhance the theme or it can take away from it due to the organization of the book.
TRADITIONAL
Freedom has not done this style of book in a long time, partially because it constitutes a more general theme and limits theme design. In a traditional book there are usually 6 sections- academics, student life, sports, clubs, people pages, and references (index, baby ads, etc.). These sections are not always but usually color coded. For example, all academic spreads are orange, all student life blue, etc.
UMBRELLA
This style of book is unique and can fit specific themes, but may also be hard for the student body to understand. With umbrella books, each spread is an umbrella topic (ex. courage, fate, bravery, etc.). WAIT YOU'RE GONNA NEED THIS is an example of umbrella coverage. Each spread was a "this" and while it allowed us to play with design a little bit more and definitely enhance the theme, students had a hard time understanding why something that happened in September was on the same page as something that happened at the end of October. With umbrella it is really important to put dates in all of the subheads for reference.
CHRONOLOGICAL
Chron is my personal favorite type of book. I think that it is easier to make the deadlines and plan the coverage. With chron books, one spread is one week of the year, and it gives you the flexibility to add theme pages wherever. You can also add more spreads for a week if it needs a lot of coverage. For example, in "this is your freedom" we had two homecoming spreads because it needed a lot of coverage. (ex. fit in STAND OUT and this is your freedom)