<p>What is the "<em>best</em>" way to store international addresses in a database? Answer in the form of a schema and an explanation of the reasons why you chose to normalize (or not) the way you did. Also explain why you chose the type and length of each field.</p>

<p><strong>Note: You decide what fields you think are necessary.</strong></p>

You need to provide a bit more details about how you are planning to use the data. For example, fields like City, State, Country can either be text in the single table, or be codes which are linked to a separate table with a Foreign Key.
Simplest would be
Address_Line_01 (Required, Non blank)
Address_Line_02
Address_Line_03
Landmark
City (Required)
Pin (Required)
Province_District
State (Required)
Country (Required)
All the above can be Text/Unicode with appropriate field lengths.
Phone Numbers as applicable.