1. Common Nouns
Common nouns name a person, place or thing. They are not capitalized.
a dog
the road
my sister

2. Proper Nouns
The names of particular persons, places or things are proper nouns. Capitalize the first word and each important word of a proper noun.
Janice Smith
Voorhees, New Jersey
The United States of America

3. Abbreviations
Capitalize the first letter of an abbreviated proper noun. Abbreviations often occur in addresses, titles and initials in names and in names of days and months. Most abbreviations end with a period.
Mr. K. C. Cougar
7 School Ln.
Voorhees, NJ

4. Calendar Words
Capitalize the days of the week, the months of the year and holidays.
Monday
March
Halloween

5. Titles Capitalize the first word and all important words in a title.
The Wind in the Willows
Beauty and the Beast