If softwoods are your only choice, your best options are Yellow Pine, Douglas Fir, and any of the Cedars.
Yellow Poplar is a poor wood for fire fuel. Though it burns and splits easily, it emits some heavy smoke and many sparks.
Southern Yellow Pine easily burns at varying heat levels and is easy to split. It emits some smoke and sparks but makes a relatively good firewood.
Douglas Fir is easy to burn and burns at a high heat level. It is easy to split and doesn't throw many sparks, but because of its smokiness Douglas Fir is just rated as a good source of fire fuel.
Cypress and Redwood are fair softwood sources of fuel. They are both somewhat easy to burn and burn at medium heat levels with some smoke and no sparks.
White Cedar or Western and Eastern Red Cedar all burn at low heat but are very easy to burn. They are easy to split, however they emit some heavy smoke and lots of sparks.
White Pine, Sugar Pine and Ponderosa Pine all easy to burn and burn at low heat levels. They are easy to burn and easy to split though they smoke some and spark a small amount.
Tamarack or Larch both burn at medium heat levels, are easy to burn and split but they both smoke and spark. They are fair sources of fire fuel, but not the best of the softwoods.
Spruce is a poor source of fire fuel because it burns at low heat, it smokes somewhat heavily and sparks considerably. Spruce wood is easy to burn and split but is not the best choice for firewood.