8 {Swamp}
8 {Forest}
3 {Overgrown Tomb}
2 {Woodland Cemetery}
_____________________________
21 land
2 {Primordial Hydra}
4 {Corpse Traders}
4 {Disciple of Griselbrand}
2 {Boneyard Wurm}
2 {Corpsejack Menace}
2 {Jarad, Golgari Lich Lord}
4 {Arbor Elf}
1 {Borderland Ranger}
_____________________________
21 creatures
1 {Gutter Grime}
2 {Grave Betrayal}
2 {Death's Presence}
3 {Unhallowed Pact}
3 {Barter in Blood}
2 {Rise from the Grave}
3 {Lair Delve}
2. {Ranger's Path}
______________________________
18 non-creature spells
Sideboard
__________________________________
1 {Predator Ooze}
2 {Boundless Realms}
1 {Splinterfright}
1 {Nefarox, Overlord of Grixis}
2 {Bone Splinters}
2 {Grave Exchange}
2 {Grave Betrayal}
2 {Death's Presence}
2 {Bountiful Harvest}
Comments are apriated
A lot of your stuff here is very controlling and seems like a lot of fun late game, but my main concern is surviving the early game long enough to get your big effects rolling. You may want to replace some of the late-end land-related stuff like {Bountiful Harvest} and {Boundless Realms} with early mana acceleration like {Arbor Elf}. Not only does this get your your late game stuff faster, but once you have your mana base established, you can use the elves as sacrifice fodder for your big effects, since they are a creature.
{Woodland Cemetary} x4 to replace 4 basic lands will help your mana too.
Another copy of Jarad might be nice too, to get him more often. His sacrifice for damage on your hydras are a big deal, and a good win strategy!
{Grisly Salvage}, {Mulch}, and {Jarad's Order} are cards for GB that I can think of to get stuff into your grave.
Your mana curve seems a bit high, should consider options like {Borderland Ranger} and/or {Arbor Elf}.
I'll put some of that in right now
Updated