The following information comes from the NFL:

A total of 32 compensatory choices in the 2012 NFL Draft have been awarded to 15 teams, the NFL announced on Monday. 
Under the rules for compensatory draft selections, a team losing more or better compensatory free agents than it acquires in the previous year is eligible to receive compensatory draft picks.
The number of picks a team receives equals the net loss of compensatory free agents up to a maximum of four.  The 32 compensatory choices announced today will supplement the 221 choices in the seven rounds of the 2012 NFL Draft (April 26-28), which will kick off in primetime for the third consecutive year.
The first round will be held on Thursday, April 26 and begin at 8:00 PM ET.  The second and third rounds are set for Friday, April 27 at 7:00 PM ET followed by rounds 4-7 on Saturday, April 28 at Noon ET.
This year, the compensatory picks will be positioned within the third through seventh rounds based on the value of the compensatory free agents lost.
Compensatory free agents are determined by a formula based on salary, playing time and postseason honors.  The formula was developed by the NFL Management Council.  Not every free agent lost or signed by a club is covered by this formula. 
Three clubs this year (Atlanta, San Diego and Buffalo) will each receive a compensatory pick even though they did not suffer a net loss of compensatory free agents last year.  Under the formula, the compensatory free agents lost by these clubs were ranked higher than the ones they signed (by a specified point differential based upon salary and performance).
Thirty compensatory picks were awarded to clubs based upon the compensatory pick formula.  By rule, two additional choices were awarded at the end of the seventh round to bring the total number of compensatory selections to 32, equaling the number of NFL clubs.  The two additional picks were awarded to St. Louis and Indianapolis based upon the 2012 draft selection order.
The following 2012 compensatory draft picks have been determined by the NFL Management Council:
2012 Compensatory Drafft Picks
3 33-95   Oakland
4 33-128   Minnesota
  34-129   Oakland
  35-130   Baltimore
  36-131   New York Giants
  37-132   Green Bay
  38-133   Green Bay
  39-134   Minnesota
  40-135   Dallas
5 33-168   Oakland
  34-169   Baltimore
  35-170   Indianapolis
6 33-202   New York Jets
  34-203   New York Jets
  35-204   Cleveland
  36-205   Cleveland
  37-206   Indianapolis
  38-207   Carolina
7 33-240   Pittsburgh
  34-241   Green Bay
  35-242   New York Jets
  36-243   Green Bay
  37-244   New York Jets
  38-245   Cleveland
  39-246   Pittsburgh
  40-247   Cleveland
  41-248   Pittsburgh
  42-249   Atlanta
  43-250   San Diego
  44-251   Buffalo
  45-252   St. Louis
  46-253   Indianapolis
Following are the compensatory free agents lost and signed last year by the clubs that will receive compensatory picks in the 2012 NFL Draft:

ATLANTA Lost: Harvey Dahl, Michael Koenen
  Signed: Ray Edwards, Reggie Kelly
BALTIMORE Lost: Chris Chester, Dawan Landry, Le’Ron McClain, Donte’ Stallworth, Josh Wilson
  Signed: Vonta Leach, Bernard Pollard, Ricky Williams
BUFFALO Lost: Paul Posluszny, Donte Whitner
  Signed: Brad Smith, Tyler Thigpen
CAROLINA Lost: Jeff King, Richard Marshall, Matt Moore
  Signed: Ron Edwards, Olindo Mare
CLEVELAND Lost: Abram Elam, Matt Roth, Chansi Stuckey, Jason Trusnik, Lawrence Vickers, Floyd Womack, Eric Wright
  Signed: Brandon Jackson, Dimitri Patterson, Usama Young
DALLAS Lost: Stephen Bowen, Sam Hurd
  Signed: Abram Elam
GREEN BAY Lost: Daryn Colledge, Korey Hall, Brandon Jackson, Cullen Jenkins, Jason Spitz
INDIANAPOLIS Lost: Charlie Johnson, Clint Session
MINNESOTA Lost: Ray Edwards, Ben Leber, Tarvaris Jackson, Sidney Rice
  Signed: Remi Ayodele, Charlie Johnson
NEW YORK GIANTS Lost: Kevin Boss, Barry Cofield, Steve Smith
  Signed: David Baas, Steve Weatherford
NEW YORK JETS Lost: Drew Coleman, Braylon Edwards, Shaun Ellis, Brad Smith, Steve Weatherford
OAKLAND Lost: Nnamdi Asomugha, Robert Gallery, Bruce Gradkowski, Zach Miller, Thomas Howard
  Signed: Kevin Boss, Stephen Heyer
PITTSBURGH Lost: Nick Eason, Keyaron Fox, Matt Spaeth
SAN DIEGO Lost: Kevin Burnett, Darren Sproles
  Signed: Travis LaBoy, Takeo Spikes
Total 2012 Compensatory Draft Picks
Cleveland 4
Green Bay 4
New York Jets 4
Indianapolis 3
Oakland 3
Pittsburgh 3
Baltimore 2
Minnesota 2
Atlanta 1
Buffalo 1
Carolina 1
Dallas 1
New York Giants 1
St. Louis 1
San Diego 1
Arizona 16
Atlanta 11
Baltimore 33
Buffalo 26
Carolina 14
Chicago 17
Cincinnati 18
Cleveland 6
Dallas 30
Denver 9
Detroit 15
Green Bay 30
Houston 4
Indianapolis 19
Jacksonville 19
Kansas City 13
Miami 15
Minnesota 17
New England 26
New Orleans 10
NY Giants 21
NY Jets 9
Oakland 16
Philadelphia 29
Pittsburgh 25
St. Louis ** 27
San Diego 18
San Francisco 19
Seattle 18
Tampa Bay 18
Tennessee *** 27
Washington 12
* 1994 was the first year that compensatory draft choices were awarded.
** St. Louis picks include those awarded to Los Angeles Rams.
*** Tennessee picks include those awarded to Houston Oilers.