Joining Raiders

You have to complete the New Reno suitcase quest first. After delivering the suitcase to Metzger, ask him about Raiders. He will send you to a bar called 'The Hole', find a guy named Stoke there. After a long discussion, he will send you to the Raider base (a new location on the map, near NCR), you will find Raynes there. Ask him about joining the Raiders, he will tell you to get rid of a farmer and his whole family (in another new location - farm). Go to that farm and do your job, after reporting it, you will be able to see another Raider base - near Broken Hills. In the cave there, you will find Miller. After paying him 4500 caps he will teach you about Level 3 of Small Guns crafting.