Titles of books need to be underlined or italicized when you refer to them in writing. Since you are hand writing this, you need to underline.
Quotation marks go around the titles of shorter works like songs or poems; or chapter titles within a book with it's own title.
If you're writing for a class, definitely remember to underline. If it's just for book club or something, I wouldn't worry about it too much, but since you know what's correct, just go ahead and do it.
Also, remember to capitalize the first and LAST word of the title, and any other words that except articles (a, an, the) and conjunctions (and, but, or) :)