The ninth and final season of How I Met Your Mother (7 and 7:30 p.m., CBS/Ch. 2) begins with a pair of episodes.We finally met the mother (Cristin Milloti) - well, future mother - at the end of last season. The new season will revolve around everyone else meeting her.I'm a little concerned about how all this will work. But I'm willing to give the show's writers the benefit of the doubt because we have eight seasons of (generally) fine work to date.Elsewhere on TV ...NFL (6:25 p.m., ESPN): Oakland Raiders at Denver BroncosDancing with the Stars (7 p.m., ABC/Ch. 4): The competition continues.The Voice (7 p.m., NBC/Ch. 5): Christina Aguilera and Cee Lo Green rejoin Adam Levine and Blake Shelton on the judging panel as the auditions begin. (Season premiere)Bones (7 p.m., Fox/Ch. 13): A management consultant is murdered ... and his body is partially eaten by bobcats. Ick.2 Broke Girls (8 p.m., CBS/Ch. 2): A new season of this unfunny sitcom begins.Genealogy Roadshow (8 p.m., PBS/Ch. 7): In this new series, folks learn about their family's past.Sleepy Hollow (8 p.m., Fox/Ch. 13): Ichabod and Abbie go after a witch.Mom (8:30 p.m., CBS/Ch. 2): Anna Faris and Allison Janney star as a daughter and her mother who are both recovering addicts in this promising new sitcom.Hostages (9 p.m., CBS/Ch. 2): In the debut of this limited-run series (scheduled to end in December), a doctor and her family are taken hostage just as she's about to operate on the president of the United States.Castle (9 p.m., ABC/Ch. 4): Did Beckett accept Castle's marriage proposal? (Season premiere)The Blacklist (9 p.m., NBC/Ch. 5): James Spader plays a former U.S. operative who turned double agent but has come out of the cold to help stop terrorists in this intriguing new series.Late Show with David Letterman (10:35 p.m., CBS/Ch. 2): Former President Bill Clinton is the guest.