There are currently 2 operations in the game. Later there will be written description on the individual bosses and how to deal with them, first just some YT videos:
ETERNITY VAULT:
Annihilation Droid XRR-3:
Video link: http://www.youtube.com/watch?v=NzlIEbWUnS4
Gharj:
Video link: http://www.youtube.com/watch?v=R64DroKqmm8
Pylon:
Video link: http://www.youtube.com/watch?v=tiiS9QDU2VA
Infernal Council:
Video link: http://www.youtube.com/watch?v=EBE-stuLbsM
Soa:
Video link: http://www.youtube.com/watch?v=dMfe0QElNbA
Take your time please selecting your individual loot choice. This is important because once you select, you can't revoke it. Certain loot items have the "Bind on pickup" attribute, which means that the player winning the roll and receiving the loot item CANNOT trade it to another player later anymore !!!
Loot item types:
Mods:
Carefully inspect the mod and understand if it is RELEVANT to your character's profession. If not select PASS, if yes then select NEED if you burn to have it to significantly upgrade your equipment
GREED should only ever be selected if all members are agreeing on not really needing the item.
Biometric Crystal Alloy: If you are NOT a crafter at all please select PASS on these ones. If you are a crafter and indeed need the alloy and intend to craft an item with it select NEED. The item will then be rolled just between the crafters that really need it. This is a highly sought after loot for crafters.
Schematics:
If the schematic is attributed to YOUR character's crafting profession (and you are sure that you don't have it already) then select NEED. Please don't select NEED if you could not use the schematic or don't even have a crafting profession. Helping our crafters will in the long run help you.
Armor/weapons:
Also with these items be sure that you can wear the armor or use the weapon at all (Example : You are light armor specced and select "Need" for a heavy armor piece") and if it really is an improvement to what you already have, so that players who are not well equipped can benefit more from it.
Relics:
In nightmare mode Karagga, a guardian relic drops that has procs that only guardians really benefit from.
Other items: Listen to calls by players who know about the loot item and want to roll for it. If you are not sure, ask in opschat or TS. Never just select NEED, if you don't know exactly what the item is.
Generally if you don't need something select PASS. You do so by clicking on the X (generally closing a window in user interfaces) located in the top right corner of the loot options window. This will exclude you from rolling for the item. Selecting GREED is not the same and would make you roll for it too.
Thank you for respecting these simple rules it will help to avoid unnecessary frustration and increase fun. )