I am having trouble deciding who to start at RB. I need to start 2.?

Definately Maurice Jones-Drew. They don't have a major ping game so Jones should get a good share of carries. San Fran has a mean defense, St. Louis ping game has suffered with loss of Laurent Robinson so they may see a lot of Blitzes to force some mistakes by the QB. Therefore I'd go with Coffee against St. Louis or Slaton against Oakland as my second RB. Good Luck