The reason im only posting 15 is because the Guide will be so long.

The Birth Of An Assassin
This is a story based trophy and you will receive this at the beginning of the game when you hop into the Animus for the first time. Watch the short scene for the birth of Ezio and the trophy will sound.

Arrivederci Abstergo
After witnessing the birth of Ezio, Lucy will tell you to follow her. Follow her out of Abstergo and avoid contact with the guards. In the parking lot you will have a face off with the guards. At the end of the escape you will receive this trophy.

Welcome to the Animus 2.0
Once you enter the Assassin's hideout and learn about the Animus 2.0, you will have to talk to everyone to proceed. Once you do that, walk up to the Animus and press any button, you will lie down and receive your trophy.

The Pain of Betrayal
Complete all the main story missions in DNA sequence 1 for this trophy.

1.Boys will be boys
2.You should see the other guy
3.Sibling Rivalry
4.Night cap
5.Paperboy
6.Beat a cheat
7.Petruccios secret
8.Friend of the family
9.Special delivery
10.Jail bird
11.Family heirloom
12.Last man standing

Vengeance
Complete all the main story missions in DNA sequence 2 to unlock this trophy.

1.Fitting in
2.Ace up my sleeve
3.Judge,Jury,Executioner
4.Laying low
5.Arrivederci

Exit the Son
Complete all the main story missions in DNA sequence 3 to unlock this trophy.

1.Roadside assistance
2.Casa dolce casa
3.Practice makes perfect
4.What goes around
5.A change of plans

Bloody Sunday
Complete all the main story missions in DNA sequence 4 to unlock this trophy.

1.Practice what you preach
2.Fox hunt
3.See you there
4.Novella's secret
5.Wolves in sheep's clothing
6.Farewell Francesco

Undertaker
This is a story based trophy and will unlock after you investigate the Assassin's tomb in the Novella's secret memory in sequence 4,retrieve the Seal of Darius and leave the tomb. All the tombs have the same entrance,a flashing skull on the wall or nook that you press circle when you are standing next to, and the entrance will open.This is an important mission as it will unlock the Assassins Tombs for exploration to obtain all 6 seals that can be placed downstairs in your Villa. Once all have been placed in their pedestals you will receive Altair's armor.

The Conspirators
Complete all the main story missions in DNA sequence 5 to unlock this trophy.

1.Four to the floor
2.A blade with bite
3.Evasive maneuvers
4.Town crier
5.Behind closed doors
6.Come out and play
7.The cowl does not make the monk
8.With friends like these

An Unexpected Journey
Complete all the main story missions in DNA sequence 6 to unlock this trophy.

1.Road trip
2.Romagna holiday
3.Tutti a bordo

Bleeding Effect
Complete the training with Lucy by turning on the outside sensors and when you wake up in the morning you must re-enter the Animus and you will then receive this trophy.

The Merchant of Venice
Complete all the main story missions in DNA sequence 7 to unlock this trophy.

1.Benvenuto
2.That's gonna leave a mark
3.Building blocks
4.Breakout
5.Clothes make the man
6.Cleaning house
7.Monkey see, monkey do
8.By leaps and bounds
9.Everything must go

The Impenetrable Palazzo
Complete all main story missions in DNA sequence 8 to unlock this trophy
1.Birds of a feather
2.If at first you don't succeed
3.Nothing ventured,nothing gained
4.Well begun is half done
5.Infrequent flyer

Masquerade
Complete all the main story missions in DNA sequence 9 to unlock this trophy.

1.Knowledge is power
2.Damsels in distress
3.Nun the wiser
4.And they're off
5.CTF
6.Ribbon round-up
7.Cheaters never prosper
8.Having a blast

Bianca's Man
Complete all the main story missions in DNA sequence 10 to unlock this trophy.

1.An unpleasant turn of events
2.Caged fighter
3.Leave no man behind
4.Assume the position
5.Two birds,One blade