Accent marks

Does anybody have a concise reference on accent marks? I'd like to know the rules!

You have to memorize them. Accent marks are used:

- When the word breaks the Spanish stress rules (below)

- When a word with an accent sounds the same as one without an accent but has a different meaning (such as el and él or como and cómo).

Spanish stress rules:

- Words ending in a vowel, n or s the stress is on the second to last syllable

- Words ending in a consonant (except n or s) the stress is on the last syllable

Thank you!