Here you are:
1. Ice March: 14 turns, starts in November 1917. The Revolution has just taken place. Bolsheviks vs. tiny White force in the south. Personal opinion: too little, too small. I think the Russian Civil War campaign (see below) should have started in Nov. 1917. Alas...
2. The Russian Civil War: 86 turns, starts in June 1918. The big one

.
You can play as any one of the three sides (Bolsheviks, Southern Whites, Siberian Whites). Personal opinion: It's the most fun, I am playing it right now.
3. Revolution Under Siege: 64 turns, May 1919. Like the one above, but the Whites have advanced and are ready to strike. You can play as any one of the three sides (Bolsheviks, Southern Whites, Siberian Whites).
Personal opinion: it's for people who play as the Whites, don't like to organize their troops as much as in the campaign above and want to jump straight to the fighting.
4. Admiral Kolchak's Siberian Coup: 76 turns, starts in November 1918. Much like the "Russian Civil War" campaign, only that Germany has already lost the war, is evacuating Ukraine and the Western Allies can help the Whites much more. Again, you can play as any of the three sides.
5. Finnish Civil war: 17 turns, starts in January 1918, ends in October. Personal opinion: fun. You can only play as Red or White Finnish forces. The Germans - who are still very much in the war - help the White Finnish forces. And the Bolsheviks help the Red Finnish forces.
6. Polish-Soviet War: 16 turns, starts in May 1920. You can play as Poland or the Soviets.
And I saved the best for last:
7. Drang Nach Osten: 71 turns, starts in January 1921. Germany has won WW1, the Bolsheviks have won the Civil War. Ukraine is a German puppet state, however the Bolsheviks are attacking it, hoping that a war with Germany will trigger world revolution (and it's actually possible for it to happen, play the scenario and you will see

). So the Germans start Barbarossa 20 years early, as to speak. Personal opinion: absolutely awesome, I love alternative history and this is very well done. As somebody from AGEOD said, it's like a game inside a game. It's huge and very awesome.
I exclude the three tutorials, obviously. If you need any more information, we're here!