Made God rank two seasons in a row with this deck, so thought I might write a guide :P
If you like this deck, please check out (and upvote :D) my other take on sacrifice with Annoying Gnat, Altar of Souls, and Radiance, Imperial Airship. It's not quite as competitive as this one, but very fun :)
This, like many other control sacrifice decks, involves stalling in the early game and capitalizing on the death of your own creatures in various ways. Your win condition is often Soul Eater, but there are other ways to win that you should keep an eye out for (discussed later).
The major difference between this and other Sac decks is that this deck includes a strong handbuff side-strategy, which benefits most when your hand is small. I like to think of handbuffing as a mini-game, in which you are calculating probability of buffs landing on certain creatures. Spirits of Rebirth and Court Jesters provide buffs to creatures in your hand, and you should try your best to focus these buffs on Deepwood Stalkers, Wind Soldiers, and sometimes Flash Salmon. These cards function as removal, and are more effective if buffed. Deepwood Stalker has especially strong potential to swing matches in your favour, as it can simultaneously remove a pesky creature (such as Azure Skywhale) and provide a body for your board.
Your goal in the beginning should be to generally play special lands only in the beginning, and get two faeria harvesters on either side of your board as soon as possible. Protect Bone Collectors. See the notes below about mulligan and specific cards:
Mulligan - In general, keep Bone Collector, Earthcraft, Demon Wrangler, Village Elder, and Eredon. Throw back Soul Eaters, Deepwood Stalkers, Flash Salmon, Wind Soldiers, Court Jesters, and Doomgate. Keep Spirit of Rebirth only if the rest of your hand is good. Keep Time of Legends only if you don't have Eredon, otherwise throw it back.
The best possible start (in my opinion) is to go second with a Demon Wrangler and Village Elder in hand. Open to one side of your orb with Explore, play the Elder on the prairie, then a desert to the other side, Wrangler on the desert to sac the Elder. This lets you establish two bodies for defense immediately, and have two faeria harvesters the next turn. If you have the absolute dream hand (which is these two cards + Bone Collector going second), you should open with a forest (to the right or left of your orb) and play bone collector, end turn. Then Explore to the same side as the Collector, move him to harvest, play the Elder to his side (next to your orb), open a desert on the other side and Wrangler sac the Elder.
This deck takes practice to master, but once you have the gist of it, it is extremely fun to play. Here are some card-specific notes that may be helpful.
====Doomgate, Door to Oblivion====
This card is tricky to use, but is extremely beneficial to the overall engine of this deck. It is best played directly adjacent to your orb (front or sides) as this allows you to hit your opponents orb the turn you summon Ostregoth. While you might be tempted to use this as soon as possible, you should NOT keep this in your opening hand. Your number one priority in the early game should be harvesters. Use this only when you have a stable supply of cheap sac fodder and can reliably buff Bone Collectors. With a Spirit of Rebirth on Board, this is especially powerful as you can consistently control which creatures in your hand receive buffs. If you can engineer a situation in which you summon Ostregoth, hit your opponent, and drop a buffed Soul Eater in the same turn, it's almost impossible to lose.
====Eredon, Voice of All====
This card is insane value in this deck, especially when dropped early. Body+Buffs to every creature in your deck can make a huge diffference, especially when playing your removal creatures.
Perhaps the most versatile card in the deck (and the deck's namesake), as it can function as removal, card draw, and or a buff. Since he is so cheap, you can drop him easily to concentrate your handbuffs on other creatures in your hand such as Deepwood Stalker. Sometimes, if Salmon has been handbuffed, he can be removal and card draw. Also, with these guys and Wind Soldiers, keep an eye out for OTK potential. I once OTK'd my opponent with Ostregoth and a 12/12 Flash Salmon :p.
Your most common win condition. These guys get huge, and that's pretty much all there is to it. While it might be frustrating when they eat a 50/50 handbuff that would otherwise land on Deepwood Stalker, this might make the difference later on between a two-turn-kill and an OTK.
====Time of Legends====
This card is included in this deck to fish out your Eredon and Doomgate when they are needed. Keep in starting hand only if you don't have Eredon. Also keep in mind that when going first, playing this may make a difference in the plays you are able to make.
Anyway, I have played both this deck and the new popular 'turbo-sac' variety pretty extensively, and find this deck to be better positioned in a wide range of matchups. The sheer amount of removal in this deck allows you to take out pesky Blood Singers or Azure Skywhales from across the board (with Wind Soldiers and Deepwood Stalkers). I hope you enjoy it as much as I do!