This list was provided at a roundtable to our troop leaders. Good ideas for scouts new and old.

Sleeping Bag - Good Quality keeps boys warm at night. Might consider a liner as well. 20 to 25 degree bag would last a long time through many activities (including high adventure). Synthetic recommended if there is a possibility of getting wet.
Sleeping Pad - insulates from the ground. Many good options - Self inflating, like a thermarest. Or Air insulated like a Big Agnes.
Backpacks - Internal or External Frame - try them on see what fits best and how they load.
Hiking Boots - make sure they have good footwear. We go to a lot of thorny, rocky campsites.
Hiking Socks (liners, wool) - Smartwool or Thurlo are good. Liners aren't necessary but some people like them.
Hiking pants (zip off legs, nylon)
Rain Gear (Ponchos, Jacket & Pants, Backpack covers) - good stuff for wet camping
Compasses - a good basic compass is a must.
Water Systems - Naligene /Canteens / Platypus - Naligene bottles are a must. At least two for a campout. Water systems are OK.
Chairs - folding for car camping, when searching for a sleeping pad see what chair options the pad has. This is valuable for backpacking.
Stoves (backpacking / car camping) - the troop provides stoves for trips we take with the trailer. backpack stoves can be purchased later.
Mess Kit / Plate, Bowl, Cup, Utensils - All they really need is a cup, a bowl, and a spoon. There are some neat very lightweight options out there.
Lanterns - troop provides these. Small flashlights are all they need.
Tents (backpacking / car camping) - set them up, try them out. This is really personal preference. Lighter the better for backpacking. They should be able to share the load on a backpack trip. If you buy one good tent it should do for all of our camping activities.
Pocket knives, sharpening stones - personal preference. Small is better. No sheath knives.
Uniforms - neckerchief slide kit, book cover, Troop Class-B ...
Books Hiking, Camping, Cooking, Dutch Oven Cooking Compass/Orienteering
Dry bags - for canoe camping and other water activities
Cot - not necessary if you have a good sleeping pad. Not encouraged on weekend campouts

Also check out the packing list for other ideas.

Check with your Unit Leader for equipment that the Unit provides Here are some places that we have used for purchasing this gear in the past.

http://www.bcstore.com
http://www.outdooroutlet.com
http://www.jomashop.com
http://www.northernmountain.com
http://www.rei.com
http://www.campmor.com
http://www.sierratradingpost.com

A source for reasonably priced used equipment http://users.scronline.com/troop77/equipmenttrader.htm