Step 1 -- Felony or Misdemeanor?
The Alabama Constitution, Article VIII, Section 177 (Recompiled), now states:
(a) Every citizen of the United States who has attained the age of eighteen years and has resided in this state and in a county thereof for the time provided by law, if registered as provided by law, shall have the right to vote in the county of his or her residence. The Legislature may prescribe reasonable and nondiscriminatory requirements as prerequisites to registration for voting. The Legislature shall, by statute, prescribe a procedure by which eligible citizens can register to vote.
(b) No person convicted of a felony involving moral turpitude, or who is mentally incompetent, shall be qualified to vote until restoration of civil and political rights or removal of disability.
So, if you have been convicted a crime, you can still vote (or register to vote for the first time) if it was only a misdemeanor. A misdemeanor is a crime punishable by imprisonment for a year or less. The important thing dividing a felony from a misdemeanor is not the actual sentence you received, but the maximum you could have received for that crime.
Crimes punishable by more than a year are felonies. If you were convicted of a felony, you need to go on to Step 2.