Translation:I stopped smoking three years ago.
All of the meanings? Here's a few if someone wants to add on to the list.
With specific time periods, it means "ago":
５分前 (go fun mae) - 5 minutes ago
When used to talk about what time it is, it means "before":
２時１０分前 (niji juppun mae) - 10 minutes before 2 (1:50)
With general periods of time, it means "previous":
前の月 (mae no tsuki) - the previous month
When used about a physical position, it means "in front of":
家の前 (ie no mae) - in front of my house