I am very confused about capitalizing prepositions in titles. I just can't seem to get it. I've googled and read a lot. 

In the following sentence, should "to" be capitalized? Why? I know some say don't capitalize short words, but others say capitalize short prepositions that act as adverbs, adjectives, r verbs. Doesn't this to act as an adverb?

I read the book How To Eat Fast at School.

thanks for any help