Be truthful, be honest...How?
Whether you have a website that is informational only, a frequently visited blog or you sell a product or service, you want your visitors to find what they're looking for.
It's important that your website suggest a level of professionalism equal to the backbone of your business.
If you say you sell red shoes, be sure you've get them. If your company provides expert service, your customers are going to look for that, and nothing less. If you conduct a forum, be sure you're information is correct and not mis-leading.