Forum Moderators: open
First and Last Names
Do not disallow certain characters simply because they don't fall between A and Z. Lots of countries, especially European, use more letters than A-Z. (ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞß ..)
Contact Information
Always give the visitor at least three ways of contacting you - Phone, Postal Mail, E-mail
Spelling and Grammar
Have someone proofread your pages, especially if English isn't your native language. But, even if it is, have someone (who is not a designer) read and comment your texts.
Product Presentation
Use actual facts. Use business references. If you don't have any, it's better to leave them out. Avoid phrases like "the best", "the original", "the (whatever)-est" - unless that is absolutely true, of course.
Can I add...
Not everbody has a ZIP, sometimes its a POSTCODE or something else
Sometimes the last name is the given name and the first name the surname as for example in Chinese names. To be helpful, the Chinese often reverse them to make it easier for Westerners. So we usually use FAMILY NAME and GIVEN NAME instead of SURNAME AND FIRST NAME. Its not perfect, but its better!
Enlglish is usually the second language of those outside the US, Canada, UK, Australia, Singapore, etc etc. Use simple clear language and keep product appeals short and sweet!
DONT ban all email from Asian servers becuase you think most spam email comes from there. We are based in Asia - even with that only 10-15% of our spam comes from Asia. Most comes from the US. You will lose a lot of valuable leads if you do.
Something that I constantly find is that US sites often insist you enter your state and attempt to verify that your postal / zip code is correct for that state, making it difficult or impossible for people outside the US to register or whatever. The US has some 250 million people - there are another 6 billion worldwide ....
Contact information - add Fax to that - there are many free fax to email services, so no need for additional phone lines
Also, give genuine contact information - I won't purchase from a company that hides behind a PO Box number - it doesn't matter to me if the company I'm purchasing from is a large corporate or a one-man band, so long as it's a genuine business with genuine contact details