Notes for the DPS Build

You'll want to get the E on them and then activate D and 1(Searing Arrows) to maximize damage. I'd save W for if they manage to escape or just throw it and combo it witl your stun. Use ult when nescessary (Try not to use it to solo an enemy, for it can be used to zone enemies out of map objectives later on)
For Tier 1 you can go either with Ranger's Mark, Pierce or Seasoned Marksman. Seasoned Marksman just wasn't as effective for me, as I am always trying to help different lanes when needed.
For Tier 7 you can go with either Bolt (A.k.a. LoL Flash), Rewind or ult upgrade. It's up to you honestly.
Be sure to make tweaks to your talents as they suit the match you're currently in.

Notes for the Support Build

On Tier 2, you can actually pick between Healing Ward or Overflowing Light. I just like the Ward better when teamfighting, because you'll most likely drop below 90%. But if you can guarantee the Overflowing Light effect, it is way more effective.
On Tier 3, you can go for any of the Light of Elune upgrades, but also the MULE if your team is getting stomped. Tho I'd still prefer the Light of Elune upgrades. Also as an option, if you have Illidan and Valla for instance (assassins), you can go for Trueshot Aura to help them attack stronger and faster.
On your Ultimate, you can actually pick any of the two freely, but I'd suggest the second only if your team knows how to handle it. It can make for strong startups, even better if you upgrade it at tier 7.
Tier 5 you can pick Lunar Blaze as well, but I'd rather have the debuff.
Tier 6 I'd pick Mark of Mending to guarantee you a self heal while your Q is on CD from healing allies or even yourself. Just more sustain. Pick Shooting Star if you need more mana sustain.
Tier 7 feel free to choose, actually any choice will benefit you well, just Storm Shield will be that tidy bit better.

So the combo for the DPS Build is pretty simple. You Stun (E), you Mark them (D), you activate your Searing Arrows (1), and just auto attack the target.
Before you mark them, you can also Ult, and after you mark and attack you can Owl them (W), but I like to save that for when they finish. If you know you can kill but they flee, use Bolt of the Storm.
GG.