Here are some articles about 18th century clothing:
There are also many books on the subject. Here's a list of a few, in Libris where you also can see if they're available at your local library.
Fashion victims : dress at the court of Louis XVI and Marie-Antoinette
Seventeenth and eighteenth-century fashion in detail
Fashion : a history from the 18th to the 20th century
Fashioning fashion : European dress in detail, 1700-1915
Historical fashion in detail : the 17th and 18th centuries