Here you will find the CIVIL WAR Questlines. Note that you must pick between the STORMCLOAKS or the IMPERIALS (this IS a civil war afterall!). You will find both questlines below. It really doesn't matter which one you pick, as there is no real difference in terms of rewards between the two. Whoever you choose to join will have YOU on their side, so just choose whichever faction you would like to win.
Take Up Arms
Join the Companions