Which words in a title should be capitalized?

The first letters. For example, Seedfolks should be capital since it's a books name and should be underlined. let me give you a hint, remember that book titles are supposed to be capital and underlined, I think that if you are writing a quote in this sign " then it has to be Italicized meaning curved.

The first word and all the important words, maybe not the smaller words like the, a, to, at, of ...