I've seen a lot of ladies asking about invitation etiquette. Martha Stewart has a lot of great guidelines! Plus a lot of other wedding ideas and advice.
Invitation Wording:
http://www.marthastewartweddings.com/228634/wedding-invitation-wording/@center/272440/wedding-etiquette-adviser
The Etiquette of Wedding Invitation Enclosures
http://www.marthastewartweddings.com/228648/etiquette-wedding-invitation-enclosures/@center/272440/wedding-etiquette-adviser
Addressing and Mailing Your Invitations:
http://www.marthastewartweddings.com/228650/addressing-and-mailing-your-wedding-invitations/@center/272440/wedding-etiquette-adviser#102906
