Start
Upon starting the game you will be given a set of quest to track down the bosses,

The easiest boss will be on the last quest added by the mod and the hardest are at the top,

Example
Quest 1 (Hard) - Quest 20 (Easy)
Steel Standing - Bury the Burier

The Bosses

-The Gravedigger - Easy
Rewards - Unique Weapon, Caps and EXP

-The Duelist - Easy
Rewards - Unique Weapon, Caps and EXP

-The Mole Rat King - Easy
Rewards - High amount of EXP

-The Desert Regulator - Average
Rewards - Unique Weapon, Caps and EXP

-The Lone Wolf - Average
Rewards - Unique Weapon, Caps and EXP
 
-The Red Axe - Average
Rewards - Unique Weapon, Caps and EXP

-The Desert Hunter - Average
Rewards - Unique Weapon, Caps and EXP

-Giant Centaur - Hard
Rewards - Gold Filled Battery, High amount of EXP

-The Dressed Killers - Hard
Rewards - Unique Weapon, Caps and EXP

-Lake Lurk Queen - Hard
Rewards - High amount of EXP

-Lake Lurk King - Hard
Rewards - High amount of EXP

-War Veteran - Very Hard
Rewards - Unique Weapon, Caps and EXP

-War Hero - Very Hard
Rewards - Unique Weapon, Caps and EXP

-The Ender - Very Hard
Rewards - Unique Weapon, Caps and EXP

-Mr. Buffed - Very Hard
Rewards - Unique Weapon, Caps and EXP

-The Combat Master - Very Hard
Rewards - Unique Weapon, Caps and EXP

-Surge - Very Hard
Rewards - Unique Weapon, Caps and EXP

-The Super Mutant Behemoth - Extreme
Rewards - Unique Weapon, Caps and High amount of EXP

-Alien Commander - Extreme
Rewards - Unique Weapon, Caps and High amount of EXP

-Enclave Sentry bot Mk V - Extreme
Rewards - Unique Weapon, Caps, Gold Filled Batteries and High amount of EXP

I've given these bosses a 30% Damage Reduction to make it harder

You may always use a Fatman if you found a boss to be challenging for you