To me rangers are really fun to use and pretty easy to understand. First of all, what should you use bows or guns? Well to me the answer is both. I have a +15 Watckeeper bow and sometimes I feel it doesn't deal enough damage to pallies even with 250% critical damage. xD
But anyway let's start with something easier first.
For talents I usually use Piercing Spear Warrior (Sword talent (level 3 would be nice for the extra hit rate), Reflex Response ( level 2!) and bow Quickdraw level 1), Sniper (Sniping (Again level 3), dashing level 1-2 and bow quickdraw level 1) and Speedy Scout (Sniping level 3, Reflex Response level 2 and bow Quickdraw level 1).
Now let's see when you should use each talent combo and what it does.
1) Piercing Spear Warrior This talent is really good against sins and other rangers (once they buff rangers are really hard to hit (even if it's only for 7-8 seconds). Keep in mind that against good sins PSW is not enough, you need to sometimes pray that Watchkeeper will proc so that you'll get 50% attack speed and 20% hit rate. Sometimes even this isn't enough so you better stack Battlefield fruits - Eye of accuracy and even get some accesory and even swords, Acc Sword of Dawn and Acc Flaming Fang.
Most of the time this does the trick and you shouldn't have that many problems hitting a sin in the level 40 arena. But if by any chance you still want more hit rate then I suggest you get the +8 hit rate sprite head gear (Holmes Hat) and the +15 hit rate sprite body gear Gallus Trousers (note: you need 16k fame with Bodor the grassland knight and some 270gold to buy it(but it's worth every coin. xD))
2)Sniper Now this talent is really good for dealing damage. I usually use this with legacy or when I want to max my critical damage I use the orange set Hawkeye (it gives +10% hit rate and +45% critical hit damage!). Just keep in mind one thing. If you use this talent combo and this set your def and HP will most likely suck big time. To use this talent combo at it's best you either need to be on a team of pally that go ahead and make everyone else attack them or if you're fighting a team of pally then you need to learn how to hit and run! (It's pretty simple you just need to learn when to use each skill, when to slow, when to use stun and when to use piercing shot.)
Note: Never use this talent against sins unless they aren't buffed and you know you can kill then before they can buff (against good sins this doesn't work as they buff right after stun effect is over).
3) Speedy Scout I usually use this when I need a bit more damage but also need some defense to deal with a sage/sin/ranger who keep stalking me. It's a decent talent combo but it will make you problems against high eva sins and the damage is not as good as the damage you get from Sniper. It's still worth using!
Well that's about it. I don't really like or use the other talents~
Now about armor. I personally like legacy because of the movement speed (most pallies have legacy and if you use legacy they will catch up to you fast and once a pally gets close to you...well you won't like it.) and because of the extra defense and HP it provides.
The orange set is good too and you should get it (and try to make/buy a few parts till you get persv (the -10% critical damage received). You will sometimes use this set (I mentioned above when) and it would be a good idea to plus it as much as possible and even add some AGI or Vit stones to it.
That's all the sets you'll want to use at level 40 (windtracker is too squishy lol)
Now weapons...running out of time. When fighting sins use watchkeeper and eye of the heart bow (put them on hotkeys and spam those 2 hotkeys, with some luck both will proc and bye-bye sin!)
When fighting pally/zerk (with bows) use watchkeeper, miracle bow (for the healing if you need to) and black serpent which won't allow them to move (trololol). Also don't forget to hit and back up. Don't let the pally and zerk get close or you'll die really fast and learn when to stun a zerk right before he bullcharges you.
These are all the bows you'll need.
If using guns (I wouldn't use guns against high eva sins, you'll have a hard time hitting them) use armored sentinel and centipede's tail (for defense and damage). Again put both guns on the hotkey bar and spam them until one of them procs then keep using the other one untill both proc.
Accessories. The best ones at level 40 are Necklace of the dead and necklace of heave. Try to get attack speed on both, Vit stat, critical rate or critical damage and acc.
Capes: Just find a cape that gives decent Vit, burn effect, unable to move, phy crit or phy crit damage.
Sprite emblems and costumes: I like using the +7-+8% phy damage and +8% phy def (I use legacy so the defense bonus is nice, eva just doesn't help me that much but it can still be useful). You should get 3 sprites and have phy attack on all 3 but eva, phy def/magic def.
Costumes(sprite) Anything that gives hit rate, attack speed, -def or the unable to move debuff (sprite's head ache or kindergarden bib from the quill altar (again trololol pally/zerks).
That's about it for now, sorry I ran out of time but if you have anymore questions I'll try to answer them after I get back.
Love And Be Loved~