anyone got a good site or a brief on how the different stats effect characters? I am trying to distribute my skill points and have no idea if endurance effects Jedi shadows enough to try and boost it.

From what I remember from the beta:

Endurance: hitpoins bonus over base provided by level/class
Willpower: force point bonus/force damage bonus
Strength: Melee damage bonus
Tech...summit or other: Proficiency with weapons
Presence: Companion damage bonus.

As a shadow your main stat would be Willpower and secondary stat is Endurance. So you shud keep appropriate gear (ie a gear with strength and tech bonus is not too useful for your class)

Strength: Melee damage (and Force damage for Knights)
Willpower: Force damage (and Melee damage for Consulars)
Aim: Ranged damage (and Tech damage for Troopers)
Cunning: Tech damage (and Ranged damage for Smugglers)
Endurance: Health
Presence: Extra health, damage, and healing for companions

There are also secondary stats, like Alacrity, which reduces cast time and cooldowns, or Crit Change and Crit Damage

This is what I have been referencing. It isn't written well but has gotten the job done.

http://www.mmo-champion.com/threads/1030602-SWTOR-Attributes-and-Damage-types

One thing that page misses:
You primary stat also affects as second type of damage (as noted above), but not quite as strongly as the main stat for that damage

EDIT: Also, Defence increases Dodge for non-force users (Dodge is functionally identical to Parry/deflect)

I could be wrong, but I've noticed a unique arrangement for base classes going into advanced classes, and how even they have a certain priority arrangement to make them most effective. The same applies to orange weapons and armor modifications. My personal experience includes:

JEDI CONSULAR
Jedi Sage (Willpower > Endurance, Resolve Mods); Jedi Shadow (Endurance > Willpower, Force Wielder Mods).

JEDI KNIGHT
Jedi Sentinel (Strength > Endurance, Might Mods), Jedi Guardian (Endurance > Strength, Guardian Mods).

The other two base classes (Trooper, Smuggler) I have not experienced enough to distinguish, but they're still fairly straightforward in matters of determining how to make your character the most effective for its proper role as a DPS, Tank or Healer. Skill trees are also an important factor to consider in those, of course.