Generators

There are 6 generators in the game. If you succesfully turn them on you get your points back. Costs shown below:

1 Player - 200
2 Players - 400
3 Players - 600
4 Players - 800

Musical Parts

Part 1 - The Grammophone is found in the excavation site, it'll be on the floor when you go down the stairs.
Part 2
-- On a ledge in a trench near the blocked door to the church
-- In the top area of the excavation site

Staff Parts (Records and components)

Part 1 (Red)
-- On a crate on the left side of Generator 6
-- Obtained from killing the robot zombies w/ claws
-- Shoot down the glowing red plane and it will drop a part which you need to pick up
-- Missing

Part 2 (Yellow)
-- By Generator Station 5 on a ledge
-- Each of the 3 parts are in In one of the giant robots (How to get in giant robot)

Part 3 (Purple)
-- By Generator Station 4 on a table or ledge
-- You need to ride the tank which is under the church to get the 3 purple parts, then you'll see a area you can jump on to get the first part (Its on the right side.) then after the tank takes a break halfway through the route and you continue to ride it there will be a part on the left and the last one will be on the right again. (Have to jump to both of them like the first part.)

Part 4 (Blue)
-- In the shelter next to Generator Shelter 2 on a shelf
-- All of the blue parts have to be dug up, they spawn randomly as far as I know.

Upon entering No Mans Land, turn left towards Generator Station 4. Right behind the first Excavation Site sign is the Record.

Maxis Drone

Part 1
-- In the tunnel behind the Church

Part 2
-- In Labratory (starting room) - always in this location

Part 3
-- In the Excavation Site by the 4 statues where you build the staffs (thanks to Niek12)

Not sure which part this is:
In the muddy tank route near Juggernog

Zombie Shield

Part 1 (any of the locations below)
-- By the "Fire" - Outside the first door to Generator Station 3 take an immediate left. Part is at the very end on a table.
-- Out first door to Generator Station 3 by the wheelbarrow in the tunnel straight ahead
-- By a box below in the trench by Generator Station 3

Part 2 (any of the locations below)
-- Upon entering the No Mans Land area, go just to the right of the MP40 into the mud area where the robots step. It should be in a corner to the right.
-- Against the back wall in the muddy area behind Juggernog

Part 3 (any of the locations below)
-- By the wheelbarrow out the door to Generator 2 in the first tunnel
-- In wheelbarrow (w/ Zombie in it) past Generator 2 and past the No Mans Land door at the dead end
-- On top of the shelter by Generator 2

Guns / Equipment

Balista (500) - Starting Building by door to Station Generator 2
M14 (500) - Starting Room
B235 (1000) - Outside the Labratory towards Generator Station 3 (stay left)
B235 (1000) - Underneth the church
Semtex (250) - Heading towards Generator Station 3 take the last left before going into the Generator Station 3 door
AK74U (1200) - Below Generator Station 3 by the steps
AK74U (1200) - In the Excavation Site
MP40 (1200) - Straight out of the No Mans Land Exit near the Excavation Center
MP40 (1200) - In the mud pit behind Juggernog
Claymores (1000) - Outside the Labratory towards Generator Station 2 in the first tunnel
Claymores (1000) - By Generator Station 5
Remington 870 MCS (900) - Outside the Labratory towards Generator Station 2 take the first left
Remington 870 MCS (900) - In the "Lightning" tunnel in No Mans Land by Generator Station 5. On the first landing.
MP40 (1300) - In the bunker next to Generator Station 2
STG44 (1400) - At the top of the church

Perks

Quick Revive (500) - In Starting Building by Generator 1
Speed Cola (3000) - In the mud by Generator 3
Stamin-Up (2000) - By Generator 5
Juggernaug (2500) - By Generator 4
Mule Kick (4000) - In Excavation Site Tunnel (may need tank to get to it)

Pack-A-Punch

Located in the Excavation Site. All 6 Generators must be turned on. You must stay in the area but do NOT need to kill the special zombies that spawn.

Shovels

By the M14 in the inital spawn in the Labratory
By first door to Generator Station 3 in starting building
"Wind" Ramp next to Generator Station 4 in No Mans Land going underground. At the bottom of the first landing to the left of the Buildable Table

Musical Easter Egg

Green glowing rock by the first door to Generator Station 3 in starting building
Green glowing rock under the shelves in No Mans Land building on the top level by the exit door
Green glowing rock by the Excavation Site when you walk up it and go left just before the part you can jump down (thanks to PFISH1)

Buildable Stations

Bottom level of No Mans Land building
"Wind" Ramp next to Generator 4 in No Mans Land going underground. At the bottom of the first landing is the Table
Underneath the church

Chest Locations (to fill Zombie souls)

-- After entering No Mans Land, turn left. Go past the Excavation site. The area at the bottom of the ramp has the chest.
-- Next to Generator 5
-- Just after the opening to the path to the church
-- Behind Juggernog

Myster Box Confirmed Items (initial list from timelordalex in another thread)

Monkeys
MG08
M1927
KSG
M1216
Skorpion Evo
Scar-H
Hamr
Galil
Five Sevens
Python
AK74u (with attachments such as extended clip)
B23R (with attachments such as extended clip)
MP40 (with attachments such as extended clip)
STG (with attachments such as extended clip)
War Machine (of course, how could it not return)
DSR

Hope this helped