Capitalization rules are among the most neglected regulations of quality writing not just on Wikipedia, but possibly in all of writing. Because of that, we're going to keep this one simple. A nice list of do's and don'ts. Keep this one handy. And show your friends:
It's italics that emphasize words, NOT capitals
Generally use lowercase letters when using someone's title, unless the word is used directly before their name (George Washington was the first American president; President Barack Obama was the 44th)
The names of offices are used as proper nouns (Both of the men mentioned above held the title President of the United States of America)
When writing about religions, capitalize names of deities and sacred texts
Capitalize The only if it is part of a composition title
In a band's name, the is generally not capitalized: the Kinks, the Ramones and the Replacements
Got it? Great.