Most of silver's points are in the Focus tree: emphasis on reduced focus/rage cost and heightened maneuverability. I'm not sure what these talents are called for a Marauder, but I will describe the important ones as I go.
First Tier from left to right
Master Focus. Decreases cd for Master Strike ( the 'saber attacks channeled over 3 seconds) and also increases its damage.
Insight. For increased Force criticals. You can't have too much crit; it is your best secondary stat. Surge is also helpful once your crit level is up.
Swelling Winds. This one enhances your Force Sweep, which is going to be your best AoE. (You leap in the air and when you come down, damage is done to nearby mobs, plus standard mobs get stunned. That one. On the Sith it's accompanied by a crackle of red lightning on the ground.) Damage will be increased by 20% and cd reduced by 3 seconds.
Second Tier
Second Wind. The ability that breaks you free of movement-impairing effects will now also heal you for 10% of your health. Doesn't increase your damage but aids hugely in survival, especially at the higher levels when 10% has become rather a lot.
Blade Focus. Reduces the focus/rage cost of Blade Storm, the ability that does a chunk of single target damage from a distance. Only works when you're in Shii-Cho form (or whatever the form is for marauders, the tree should tell you).
Third Tier
Saber Strength. Increases damage done by Zealous Leap. ( Increases damage done by Slash, too, but Slash gets less and less useful as you go on.)
Zealous Leap. This is the defining ability of the Focus tree, an extra leap that does a chunk of damage while swiftly moving you to your next nearby target. You do have to target but do not have to be facing your target to make the leap. You REALLY want to take this one.
Pulse. Eliminates pushback casting Force Stasis/Choke.
Fourth Tier
Felling Blow. Proc'd by Force Leap and Zealous Leap. Gives you an automatic crit on your next Force Sweep.
Singularity. Each tick of Force Stasis/Force Choke and Force Exhaustion (your final ability) will increase the damage done by–guess what–Force Sweep. By 25%. And it stacks. Force Sweep is now your best damage ability. You want to use it lots, even on single targets, because by the time all these talents proc and stack it hits HARD.
Fith Tier
Gravity. Reduces the focus cost of Force Exhaustion. Also of Leg Slash, if you use that at all.
Agility Training. The third ability in the Zealous Leap chain, it increases movement speed by 40% for 5 seconds after each Zealous Leap. If your ZL is on cooldown, this helps you reach the next mob faster so you can keep doing damage–Force Sweep having a limited range makes this important.
Shii-Cho Mastery. Increases armor pen while in Shii-Cho form. I forget the name of it on the Sith but it's the first form learned.
Sixth Tier
Force Resonance. Increases crit damage of Force attacks by 30%. Essentially it's a big chunk of Surge. If your crit rating's high, this talent massively increases your damage.
Enduring. Helps reduce damage. Only by 4%, but I had to put points somewhere to get to Force Exhaustion, and by this time Slash had ceased to be useful.
Final ability: Force Exhaustion. A powerful DoT that also slows target's movement speed. Very useful fighting any mob Strong or above, and highly annoying to enemy players, too. It does use quite a bit of Focus/ Rage, so I cast it following Force Stasis/Force Choke in my rotation. Taking the Gravity talent also helps keep the cost down.
Second Talent Tree:
Combat (the middle tree) first tier
Jedi Crusader. Grants a focus/rage point when you use Rebuke, the ability that reduces your damage and slightly damages the enemy. (Part of what I call my oh-shit bar.) Helps keep your rage up in a prolonged and difficult combat.
Duel Wield Mastery. Makes your offhand do 36% extra damage. 'Nuff said.
Second Tier
Steadfast. Increases Accuracy by 3%. Nice thing about this one: it reduces the need to put Acc on your gear, letting you stack more crit instead.
Stagger. Force Leap stuns for 1 additional second. This often makes the difference in allowing me to use Pommel Strike, the 'saber hilt attack that only works on an incapacitated target.
I had, but got rid of, the third tier talents for Slash, one of the most early basic attacks. I stopped using it entirely after getting all the talents for Force Sweep. Also I never use Zen so did not put the talents into that. I put my centering stacks into Transcendence for movement speed or Inspiration for extra heals. All the extra movement speed stuff adds up and gets me very quickly from one mob to the next, reducing the wasted time spent running between mobs.
The focus Sentinel is speedy and bouncy, and lots of fun to play IMHO! 
