Hi, and welcome to bass playing!. There are plenty of method books out there. Franz Simandl method books are some that a lot of us began learning with. There are also methods and etude books by 100s of others. A good place to research all titles is at a good sheet music store, like Robertson's Violin Shop in Albuquerque, NM. or online at SheetMusicPlus. BUT the main thing is to get a private teacher who can guide you through any books that he/she uses or that you want to know. Playing the bass is learned best by having a private teacher to guide your progress and to encourage that you practice. If you don't want to practice, you won't learn to play. Best of luck!