In the 1930 census I found 14 James Lafferty's in Michigan.
Start out by gathering whenyour grandparents were born and when they died and where they were born and died.You might go to your local library and see if the have the obituaries for your grandparents.It would give you a start.Generally Libraries have a genealogy department and they might help you. They can help with census and other information and also have access to newspapers with the obituaries in them. The libraries have access to roots search of ancestry.com or other websites that can help you.
Also you can go to the Mormon Church and they have a genealogy library that keep certain hours and if you go there they can help you.Call the church you do not have to be a member and they do not push religion.Its a neat place.
Also they have a free geneology program where you can keep all your notes and information starting with yourself on back.
That is how I got started learning about my dad family as both my parents were dead by the time I was 13 and the people who raised me knew very little about my dad's family.My dad was also James Lafferty.I have a half brother named Walter but its a different section of the contry.