To translate all the abbreviations:
2LT - 2nd Lieutenant (O-1) new officers, also called cherries
LTC - Lieutenant Colonel (O-5) normally battalion commanders (in command of several hundred Soldiers)
NCO - Non-commissioned officer (ranks of Sergeant to Sergeant-Major of the Army) these guys are the backbone of the army and enforce regulations, in addition to being the most experienced warriors you'll meet in the army.
E-# - Enlisted - Paygrade - pretty much another way of denoting rank. For example, E-5 type is pretty much synonymous with sergeant, even though it really designates paygrade.
O-# - Officer - Paygrade - pretty much another way of denoting rank
TL - Team Leader - normally a sergeant (E-5), in command of a 4-man fireteam within a squad
SL - Squad Leader - normally a staff sergeant (E-6), in command of an 8-man squad composed of two teams, where he is the 9th member of the squad
PSG - Platoon Sergeant - normally a sergeant first class or master sergeant (E-7 - E-8). He's the assistant platoon leader and teaches the platoon leader how to lead, enforces the rules the platoon leader sets out, and does most of the work in the actual process of organizing a platoon.
PL - Platoon Leader - normally a second lieutenant (O-1). Leads a platoon of 4 squads and a headquarters element, around 40-50 men. Bad ones don't listen to the PSG, good ones do.
1SG - First Sergeant - normally a master sergeant, occasionally a sergeant first class (E-7 - E-8) but they do have their own shiny ranks. It's just the master sergeant insignia with a diamond in the middle. They do what the PSG does, just for a company commander, not a platoon leader. They're also not second in command for a company, that goes to the XO - the executive officer, which is another officer position.
CO - Company Commander - normally a captain (O-3), leads a company of 120 men or so.
SF - Special Forces - badasses
ODA - Operational Detachment - Alpha - what SF calls its squads
CoC - chain of command
Actually, you'd be surprised how much you can find on the Army on the internet. I know for a fact that there's at least a couple websites (such as Army Study Guide) that are dedicated to enlightening people on the mysterious ways of our Army (
) and our Field Manuals are floating around pretty much everywhere. Most people wouldn't have the obsession with the Army to read them, though, unless they actually were in the Army, so I suppose you're sort of right. I am in the Army, yes, though, to answer your question.