I pretty much planned my Ranger class this way:
Starting perks: Bully & Guerrilla
Future perk: Glass Cannon - Quickdraw - Elemental Ranger
Primary Weapon: Bow
Ability priority:
Sneaking Lv 5 (Base 3 +1 Gear +1 Cautious)- for 1 AP combat sneak
Marksman Lv 5 For Quickdraw -1 AP Bow shots
Scoundrel Lv 2 For Charm Person AP cost reduction

Skill picks
First 3 should always be:
Tactical Retreat (Marksman): Easy Escape - later on allow you to leap in offensively.
Hide in Shadows (Scoundrel): Vanish for easy escapes, five rounds to drink potions. Taking damage/Using a skill breaks it.
Fast Track (Scoundrel): Hastes. Great opener.

Marksman
Ricochet: Hits up to 4, creates pool of blood. Throw lightning bolt/arrow for stuns. Can't miss.
Precision/Power Stance : Crucial. Precision for those hard shots, Power to nail Stun/Knockdown victims.
Rapture: 15 meter Charm skill. Needs level 10 though. 5 AP is too good.
Barrage: A standard 3-shot on single target. Inefficient use of AP, but works well when Sneak Attack is not an option.

Scoundrel
Charm Person: 3 meter range Charm. 6 AP cost. You get it much earlier than Rapture. Very helpful. If you think 3 meter is too short, you have a 15 meter leap. Think about it.
Other scoundrel abilities require dagger to use - so you won't use much till late game.

Geomancy
Midnight Oil: Slows - Triggers Bully damage bonus. Fire Arrow to ignite it is nice to. 3 AP. Cheap. If you give your fighters bully as well, this turns into a party buff.
Summon Spider: Great damage, great tanking, low AP cost. What's not to like?