Peg posted listings from the 1930, 1920 and 1880 census. Nowling is a rare surname, and "Narvie" is a rare given name. You are lucky; people whose ancestor was John Smith have problems.
Your best bet would be to go to a Family History Center, which many large LDS churches have. They are usually open late at least one day a week. They don't try to convert you. They get people started ALL the time. You could also see if your county Genealogy society has beginners' classes. Finally,there are several on-line guides on beginning genealogy on the Internet.
http://www.tedpack.org/begingen.htmlhttp://www.tedpack.org/begingen.html is neither the best-written nor the most comprehensive, but it has the best jokes. That is primarily because the others don't have jokes. It has a link to a better-written and more comprehensive site.
Looking at Peg's data:
1930 Florida/Santa Rosa Co/Milton W.D. Nowling 50 Fla Fla Ala Furniture salesman Myrtle 27 Fla Fla Ala Narvie 17 Fl / William 15 Fl / Harold 13 Fl / Lois 9 Fl
In 1930 your grandfather Narvie was 17, born in Florida, living with his father, W. D. Nowling in Milton, Santa Rosa County, Florida. WD was 50 in 1930 and a furniture salesman. Those three states - "Fla, Fla, Ala" are WD's birth state, his father's birth state and his mother's birth state.
Narvie had siblings or half-siblings William, Harold and Lois. Myrtle was WD's wife but not Narvie's mother, since she was just 10 years older than him.
--------------------------------------------------- 1920 Florida/Escambia Co /Pensacola/506 N. G Street William D. Nowling 42 Fla Fla FLa Furniture Collector Alice 34 Fla Fla FLa Horace E. 18 Fl US Army / Etta 16 Fl / Ernest 11 Fl / Arthur 9 Fl / Narvie 7 Fl / Willie May 5 Fl / Harold 2 ?/12 Fl Laura Keith(lodger) 24 Fl Fl Fl Saleswoman/Grocery
In 1920 William D is 42 (2-year discrepancies are common in the census) and he thinks his mother was born in Florida, not Alabama. (Birth state mixups are common too.) Narvie has older siblings, who are either on their own or dead in 1930. Alice is probably Narvie's mother. From Horace's birth, William married Alice when she was 16 and he was 24.
----------------------------------------------- 1880 Florida/Jackson Co John Knowlin 32 Ala Ala Ala Farmer Catherine 28 Fl Fl Fl Mary 9 Fl / Middy 5 Fl / Ida 3 Fl / William 2 Fl Rebecca(mother) 55 Al Al Al Lulu Grist(other) 17 Al AL AL
In 1880 there is a William Knowlin in Jackson County. (Surnames aren't always spelled the same from census to census.) "William" is much more common that Narvie. The state and birth year are right, however. If this William is Narvie's father, then Narvie's Nowling grandparents were John, born about 1848, and Catherine, born about 1852. John's mother was Rebecca.
These are only clues. They give you a county to start looking in. Obituaries, death certificates, cemetery records, other census records, local history rooms in the library, SSN applications, county history books will all help confirm and flesh out.