King Lear says that he is 'a man more sinned against than sinning':

Close pent-up guilts,

Rive your concealing continents, and cry

These dreadful summoners grace. I am a man

More sinned against than sinning (King Lear, 3.2.59)

From which one of Shakespeare's plays did the line "the naked truth" come?

"The naked truth" is from Love's Labour's Lost (5.2) and here is the passage:

DON ADRIANO DE ARMADO: The naked truth of it is,
I have no shirt;
I go woolward for penance.
BOYET: True, and it was enjoined him in
Rome for want of linen: since when,
I'll be sworn, he wore none but a
dishclout of Jaquenetta's, and that
a' wears next his heart for a favour. (735)

Where is the quote "This blessed plot/this England" found?

The passage comes from Richard II (II.i), and is spoken by the noble John of Gaunt:

This royal throne of kings, this scepter'd isle,

This earth of majesty, this seat of Mars,

This other Eden, demi-paradise...

Where can I find the passage about the seven ages of man?

The seven ages of man comes from As You Like It (II.vii) and is spoken by Jaques. It begins:

All the world's a stage,

And all the men and women merely players:

They have their exits and their entrances; 145

And one man in his time plays many parts,

His acts being seven ages.

Where does "you've hoist yourself on your own petar" come from and what does it mean?

The phrase to which you refer is found in Hamlet (4.1.206): "For 'tis the sport to have the enginer/Hoist with his own petar..." ie. to cause the engineer to be blown up by his own bomb; that is, to cause a person to be destroyed by his own deeds. The word petar is obsolete and is synonymous with Petard (n), which is defined to be a pasteboard bomb used in fireworks. The word origin is Latin (pedere).

From which work is the quote: Love is blind...?

The quote is from The Merchant of Venice: "But love is blind, and lovers cannot see/ The pretty follies that themselves commit" (2.6.38-39)

Where does the quote "...as civil as an orange..." come from?

The quote is from Much Ado About Nothing: The count is neither sad, nor sick, nor merry, norwell;/ but civil count, civil as an orange, and something of that jealous complexion.

Where can I find the quote "The first thing to do is to kill all the lawyers."?

The passage comes from the second part of King Henry VI (Act IV, Scene II). This was an actual suggestion proposed by Wat Tyler in the earlier rebellion of 1381.

Where can I find Saint Crispian?

The famous passage ("We few, we happy few, we band of brothers") about St. Crispin 's Day comes from Henry V (4.3.43-70).