What to Capitalize in a Heading or Title When Using Initial Caps
1. ALL nouns
2. ALL pronouns
3. ALL verbs, no matter how short. That means "is" and "are" always get capitalized
4. ALL adverbs and adjectives
5. ONLY prepositions over 3 letters in length - e.g. NOT "at" or "in" but "With," "Before" and "Along"
6. ONLY articles over 3 letters in length - e.g. NOT "a," "an," "the" but "There," "This," and "That"
7. NO conjunctions under 4 letters in length - e.g. NOT "for," "and," "or," "nor," "yet", "so," or "but"
8. ALWAYS the first word, no matter what part of speech
9. ALWAYS the last word, no matter what part of speech
Confusing? Yep. English often is. But I didn't make this stuff up. I did teach it to college freshmen for a couple of years, however, so that helped drill it in. Don't take my word for it, though. Here are some further sources. I'd link to more authoritative ones like the AP or Chicago Manual of Style, but they all have their content behind pay walls.
- Government Printing Office - Style Manual
- Search Engine Journal - Title Capitalization in the English Language
- Your Dictionary - Rules for Capitalization in Titles
I'm sure this can use some refining, and I'll update it in the future accordingly. And I welcome your suggestions.