First and foremost (and strangely), this is an "Aggro" deck, but not Aggro in the traditional way. "Spell-Aggro" is what you could probably call this. Just like a "normal" Aggro deck isn't doing its job if it isn't attacking, this deck isn't doing its job if it hasn't milled the opponent every turn. So, play your spells, don't hold onto them (unless specific requirements are needed, like Archive Trap's {0} cost trigger).
Now for a rundown of the cards and their interactions:
Creatures:
Hedron Crab - Mills for each land. Works well with the 8 fetch lands. You could even use Ghost Quarter on your own land in a pinch.
Jace's Phantasm - {U} for a 1/1 flier isn't great, but 99% of the time, this is {U} for a 5/5 flier, making it an awesome defender of your life total and a possible alternative win condition.
Manic Scribe - Delirium is easy to aquire. Fact: you creatures will die. Fact: you're playing fetch lands. Fact: you're playing ever instant and sorcery you draw. I'll say it again, getting Delirium is easy.
Instants and Sorceries:
Glimpse the Unthinkable - THE BEST mill card for its cost, and arguably the best mill card overall. You will play this every opportunity you get.
Mind Funeral - Not as great as Glimpse, but a strong contender for second best mill card. Remember, each fetch land the opponent uses reduces the number of lands they have in their library, making this better each fetch land used.
Archive Trap - About 90+% of Modern decks use fetch lands, which means 90+% of the time this is a free mill card. If you have multiple in hand when the opponent uses a fetch land, play all of them. Additionally, anyone foolish enough to fetch a land off Ghost Quarter also allows you to cast this for free.
Crypt Incursion - This deck wins off the inevitability off milling the opponent, but sadly until you do mill the last card, the opponent can still win. This helps you last a little longer. Additionally, this is an instant, so you can hose any graveyard strategies too.
Visions of Beyond - Sad truth, you'll run out of spells to cast very quickly. In this deck, this is an Ancestral Visions without the Suspend, making it a great way to refuel and allowing you to continue milling.
Artifacts:
Ensnaring Bridge - You should have an empty / near empty hand 90+% of the time, making this the best defence you have against creatures.
Mesmeric Orb - Do not be afraid to play this. Remember, because you almost never attack with the few creatures you do have, the only thing ever untapping on your side of the battlefield are lands. Your opponents on the other hand have all sorts of stuff untapping (including their lands). If not, that means you win more as everything else you play does mill them more than this will mill you.
Lands:
Flooded Strand; Marsh Flats; and Polluted Delta - In addition to the usual mana fixing, these also make Hedron Crab awesome and reduce the chances of drawing lands, allowing you to draw more mill effects.
Ghost Quarter - This combo'd with Archive Trap makes most opponents opt to not fetch a land, turning this into a Strip Mine.
Shelldock Isle - Getting this online is easy, so it basically says {U}: Play the Exiled card. Tip: always "Hide" a mill card.
Sideboard:
Set Adrift - "Removal" for any nonland permanent. Remember to do this before milling.
Crypt Incursion and Profane Memento - More defence against creature strategies.
Extirpate and Surgical Extraction - Sometimes you need something gone, permanently. Note, these are Instants, so you can exile anything that causes a shuffle back (*cough*Tentacruel*cough*)
Ratchet Bomb - Destroys a wide variety of things, sometimes all at once. Note that with the revision of the rules for double faced cards, this no longer kills Werewolves (or other double faced cards) as easily. Still hoses token though.