In text, company names can be what they might be called in conversation (Sherwin-Williams, not The Sherwin-Williams Co.). In resources use the business name as it appears on the “About Us” or “Contact Us” page or in comparable text on the website. (clarified 5.14.14)
Capitalize the first letter in a business name, even if the business uses a lowercase letter in its logos and promotional materials. The exception to this rule is a business name such as eBay, where a logical internal letter is capitalized instead of the first letter. And when eBay starts a sentence, cap the e.