Do You Underline Or Put In Quotes The Name Of A Book? What About It's Subtitle?

Titles of full-length works (books, movies, CDs, etc.) are italicized when typing (underlining was back when typewriters couldn't or if you're writing by hand, which isn't the case here). The subtitle is also italicized and there is generally a colon placed between the two if you're using it in a sentence rather than a single cover slide.

Shorter works (poems, songs, short stories, etc.) use quotation marks.

If it is a book you either underline it or you put it in italics. You put quotes around songs tiles and poems but not books. Movies are treated the same way as books.