Sexaholics Anonymous (SA) is one of many twelve-step programs based on the original Twelve Steps of Alcoholics Anonymous. SA takes its place among various 12-step groups that seek recovery from sexual addiction: Sex Addicts Anonymous, Sex and Love Addicts Anonymous, Sexual Compulsives Anonymous and Sexual Recovery Anonymous. Collectively these groups are referred to as "S" groups since all their acronyms begin with that letter: SA, SAA, SLAA, SCA, SRA.
SA helps recovering "sexaholics." According to the group, a sexaholic is someone for whom "lust has become an addiction." Thus SA distinguishes itself from other S groups by defining sexual sobriety as no sex with self or with partners other than their spouse. In 2001 The author of the SA White Book further refined this definition to mean a spouse in a heterosexual marriage. However homosexual sexaholics aren't excluded from participation in SA meetings and some homosexual SA groups have been formed under the traditional AA name of "Live and Let Live."
The group uses the book "Sexaholics Anonymous" (often referred to as "The White Book") as a guide. The book explains that "the sexaholic has taken himself or herself out of the whole context of what is right or wrong. He or she has lost control, no longer has the power of choice, and is not free to stop."

More info, help links & Source:
http://en.wikipedia.org/wiki/Sexaholics_Anonymous