[RPG] Most effective way to put enemies to sleep

That is a very hard question to answer, because it depends on tier and what you mean by the numbers. However, here are my leading candidates.

• Cleric. The cleric has more utility heals than any other class, and its heals are bigger. You can't overestimate the power of adding the Wisdom modifier to most of your heals, plus the cleric has an at-will that heals, which is unique to that class. When you want to bring someone from bloodied to full hit points in one go, you want the cleric.
• Warlord. The warlord's heals aren't as big, but if you take the Fight On paragon tier feat you can pump out four Inspiring Words an encounter by level 16; this is good flexibility.
• Bard. The bard's heals aren't particularly big either, but a valorous bard produces a ridiculous amount of temps -- particularly if she's a tiefling with the Stirring Song of Baator feat and a flaming weapon. And the great thing about temps is that they're not wasted if someone at full health receives them.
• Shaman. You want to go Protector Spirit for best effect; your heals are, again, not huge but you can heal multiple people at once with flexibility no other class can match.

To summarize: clerics win for huge single-target healing. Warlords probably have the most stamina. Bards are right up there with warlords, albeit via temps rather than pure heals; and shamans are unmatched for party healing.

(And of course, there's nothing wrong with the ardent or the runepriest. Runepriests give really good buffs to their party, which is the other half of the leader's role; ardents have a superb range of at-wills and also grant temps rather easily. A well-played leader speeds up combat by buffing allies along with healing.)

A Human with a shoto:

another possibility (this is what one of my players did) is to get a standard lightsaber and a shoto then get the Shoto Focus talent (from jedi academy). So long as you wield both and just attack with the shoto you get +2 attack. Then you can build towards having the dual-weapon fighting feats to get more attacks. Feats-wise you can't go wrong with weapon focus (lightsabers). If you're going two-weapons then Dual-weapon fighting 1 is a good choice to build towards future feats, alternatively Force Training could be useful, especially with Battle Strike and a lightsaber form (I'd recommend twin strike if you're going with two weapons).

At low level, you'll mainly just be holding two light sabers. But with the build, you'll be attacking with shoto focus or a twin-striking lightsaber form.

Looking here:

You'll probably want to start multiclassed for skill versatility.

Like everything, your build and powers depends on what you want to do. But in general, SWSE rewards multi-classing. Starting with Scout, Scoundrel, or Noble will give you much better starting skills and feats then a Jedi. Multiclassing gives you more Talents. And multiclassing lets you cherry pick the best Talents.

A standard untouchable Jedi build goes something like Scout 1/Jedi 1-3/Scout 2-5/Scoundrel 1/Jedi Knight X/Jedi Master Y. This gives you Evasion, Uncanny Dodge, Fringe Savant (all Scout), Block, Deflect (Jedi), Fool's Luck (Scoundrel), Skill Focus Use the Force (feat), Soresu, Shii-Cho, (Lightsaber Forms, and yes, you can use more then one at a time) + Serenity (Jedi Master).

Evasion + Uncanny Dodge + Block + Defense + lightsaber forms gives you untouchably strong defenses.

While the untouchable build is outside your nominal requirements, it does seem like an excellent thing to build towards at the early-game to allow you to survive to get the mid-game dual wielding feats.

Also, ewoks apparently make excellent dual wielders. Your chances of party-kill go up to 110% but... sacrifices must be made?

It looks like most of the options that you want are located in the Jedi Academy Training Manual. (Handy list of lightsaber forms)

Critically:

Form VI: Niman You use a very general form that covers all the bases. This is the "jack-of-all-trades" style of lightsaber combat. Prerequisites: Wisdom 13. Form I: Shii-Cho. Weapon Proficiency(Lightsaber) Benefits: You gain a +1 bonus to Reflex, Will, and Fortitude Defense. You also gain an insight bonus to attack rolls equal to your Wisdom modifier.

This should allow you to overcome the penalties of dual-weapon fighting (to a playable degree at 1st) without an overly-onerous feat investment, especially with the Shoto (or ewok dual shotoing) design.

Of course... it seems that the above class is a houseruled class, so YMMV.

Looking here we again see reference to the shoto and specialized crystals.

It looks like the answer to your question is:

At early levels, use a shoto for mainly defense and blocking, and improve your agressive stance with it by going into the jedi knight PrC as well as the dual wielding feat line.