do you underline book titles? or put them in quotes?

Either underline or italicize them.

=)

yes

When it comes to writing, the formatting of book titles depends on the style guide you are following, such as MLA (Modern Language Association) or APA (American Psychological Association). In MLA style, book titles are generally italicized, while in APA style, book titles are placed in sentence case and enclosed in quotation marks.

To be certain about the correct formatting, it is always a good idea to consult the specific style guide recommended by your instructor, publisher, or organization.

If you are using MLA style, for example, you would italicize book titles. In APA style, on the other hand, you would enclose book titles within quotation marks. Here's an example:

MLA: I just finished reading To Kill a Mockingbird by Harper Lee.
APA: I just finished reading "To Kill a Mockingbird" by Harper Lee.

Remember to be consistent with your formatting throughout your writing to maintain clarity and adherence to the chosen style guide.