Here's a bit you'll find useful then: (this is cut/pasted from a fan site that obviously used the data from the technical manual. Saves me a lot of typing.)
The Squad is the basic element of the Colonial Marine Corps, being necessary to carry out all manner of missions. These individuals are, typically, highly trained and skilled in all manner of various warfare and technical arts, and each are valuable resources to the success and completion of any mission they are sent to perform.
A rifle squad consists of four marines, including a Corporal/Lance Corporal, and two Privates/Private First Class. Each squad divides into two-man fireteams: the Rife Team and Gun Team. The Rifle Team consists of a pair of riflemen assigned together on the 'buddy' system, both equipped with the M41A1 Pulse Rifle. The Gun Team is made up of a rifleman with an M41A1 and a Machine-gunner carrying the automatic M56 Smartgun.
Two rifle squads, led by a Sergeant and riding with a driver in an M577 APC, make up a section. In a drop operation, a UD-4 dropship is attached to the section from the aerospace company team.
Two sections, led by a Lieutenant, for a rifle platoon, for a total paper strength of 25 Marines including the APC and dropship crews - though in practice this total is often less. Platoons commonly carry one or two synthetics in a technical or scientific advisory role, and to assist as medics or backup drivers/pilots.
Organic Support weaponry available to the platoon usually includes eight M240 Flamethrowers, eight UA-571 remote sentry guns, two M78 PIG phased-plasma guns or M5 rocket-propelled grenade launchers, eighteen M83 SADAR anti-tank smart rockets, and a single M402 multiple-launch fire-support mortar. Sufficient sensor equipment to establish an overlapping detection matrix with a frontage of 1,000 meters is also carried.
* A typical Colonial Marine Rifle Squad consists of 4 Marines:
o 1 Rifle Team (2 men [one will be a Corporal] armed with M41A1 Pulse Rifles and 1 M314 Motion Tracker)
o 1 Gun Team (1 man armed with 1 M41A1 Pulse Rifle, and a M314 Motion Tracker and 1 man armed with an M56 Smartgun)
* A typical Colonial Marine Rifle Section consists of:
o 2 Rifle Teams each commanded by a Corporal
o 1 Sergeant as Section leader.
o 1 UD-4 Dropships including 1 pilot and 1 weapons officers (In drop operations)
o 1 M577 APCs
* A typical Colonial Marine platoon consists of:
o 2 Rifle Sections
o 1 Officer, typically a Second or First Lieutenant commanding the Platoon.
o 1 Artificial Person/Android
o 2 UD-4 Dropships including a pilot and a weapons officers with each (In drop operations)
o 2 M577 APCs
U.S. Colonial Marine Corp. Standards of Unit Organization
1 Rifle Team and 1 Gun Team (4 men) form a Rifle Squad commanded by a Corporal/Lance Corporal
2 Rifle Squads (8 men) form a Section commanded by a Sergeant
4 Rifle Squads (20 men) and a Command squad (2 to 6 men) form a Platoon commanded by a Lieutenant.
3 to 4 Platoons form a Company commanded by a Captain.
3 to 4 Companies plus a Support Platoon form a Battalion commanded by a Colonel.
2 to 3 Battalions plus Support, Logistics and Medical Platoons to a Regiment.
A typical Brigade/Regiment will average 14,000 Support and Combat soldiers.