Below are the details from the USPS regarding proper formatting for international shipments.  Seeing these usps.com links, and reviewing the addressing for the country you are shipping to can greatly increase the speed of delivery in sorting to the country, and speeding delivery to the customer when it gets to the town.

http://www.usps.com/international/addressingintlmail.htm
http://pe.usps.gov/text/imm/immc1_007.htm

The following information is from the USPS.com links above, and is helpful for eBay shippers sending items internationally.

I often find it difficult to decipher foreign address formats, including those with provinces or areas not usual in the United States.  While you may still need to research the particulars for the country you have sold to, the below information can help.

• Delivery addresses in all uppercase letters, printed, or typewritten, IN INK, on the right half side of envleope/package.
• If possible, addresses should have no more than five lines.
• The full address should be typed or legibly written in English—using Roman letters and Arabic numerals—and should be placed lengthwise on one side of the item.
• The name of the sender and/or addressee may not be in initials except where they are an adopted trade name
• Mail may not be addressed to Boxholder or Householder.
• For parcels, addresses should also be written on a separate slip enclosed in the parcel.
• An address in a foreign language is permitted if the names of the city, province, and country are also indicated in English.
• Mail may not be addressed to a person in one country “in care of” a person in another country.
• The delivery address should be printed in all uppercase letters. The name of the place of destination and the name of the country of destination must be written in capital letters together with the correct post code number or delivery zone number, if any. The last line of the address must show only the country name, written in full (no abbreviations) and in capital letters. If possible, the address should have no more than five lines.
• Due to heightened security, many foreign postal administrations require complete sender and addressee information in roman letters and arabic numerals on postal items. The complete address of the sender, including ZIP Code and country of origin, should be shown in the upper left corner of the address side of the envelope, package, or card. Only one return address may be used. It must be located so that it does not affect either the clarity of the address of destination or the application of service labels and notations (postmarks, etc.).
• Global Express Guaranteed destination addresses must be written completely in English.
• The last line of the address block area must include only the complete country name (no abbreviations) written in uppercase letters.
• Foreign postal codes, if used, should be placed on the line above the destination country.

The following shows the order of information for the destination address:

LINE 1: NAME OF ADDRESSEE
LINE 2: STREET ADDRESS OR POST OFFICE BOX NUMBER
LINE 3: CITY OR TOWN NAME, OTHER PRINCIPAL SUBDIVISION (such as PROVINCE, STATE, or COUNTY) AND POSTAL CODE (IF KNOWN)
LINE 4: COUNTRY NAME (UPPERCASE LETTERS IN ENGLISH)

The following are examples of properly formatted delivery addresses:

MS JOYCE BROWNING
2045 ROYAL ROAD
LONDON WIP 6HQ
ENGLAND

MS JOYCE BROWNING
2045 ROYAL ROAD
06570 ST PAUL
FRANCE

The following format should always be used for destination addresses to Canada:

MS HELEN SAUNDERS
1010 CLEAR STREET
OTTAWA ON K1A 0B1
CANADA

NOTE: ONE SPACE MUST BE IN BETWEEN THE PROVINCE (I.E. ON FOR ONTARIO), AND THE BEGINNING OF THE POSTAL CODE

Sender’s Return Address

A return address showing the sender's complete name (no first name initials unless trademarked)and address is required.
Your name and address, including ZIP Code™ and country of origin, should be shown in the upper left corner of the address side on all mail.