Ranger Guide by Radiënt: Aim for Perfection/Sub

Warrior

Monk

Without a doubt, one of the more powerful (if not the most powerful) support job a ranger can wish for. Berserk adds 25% attack and ranged attack and that on top of Velocity Shot! Toss in a Warcry too while we're at it. All the offensive goodies you'd want as a ranger.
However, there are two drawbacks:
Unlike Velocity Shot, it's duration is only 3 minutes with a 5 minute cool down.
And unlike Samurai and Ninja set as support job, Warrior adds absolutely nothing to your defensive arsenal, infact berserk lowers the already low defense you have as a ranger. This support job is generally used for zerg fights, I wouldn't recommend it for exp parties from 24 to 75.

The extra hitpoints from choosing Monk as your support job helps you take another hit or two. But practically, you might as wel use Ninja instead. It offers no offensive bonuses like Warrior and no defensive bonuses like Ninja.

White Mage

Black Mage

This is the support job for the lack-of-a-real-healer-to-get-enfeebles-off-the-other-party-members. It provides no offensive bonuses or defensive, the occassional Cures would only stagger the inevitable if it happens.

Warp only, although I suppose the extra Intelligence boost from this might help on certain ammo types. But not really worth losing the benefits from other support jobs such as Warrior or Ninja.

Red Mage

Thief

If you were a Paladin, this would be pretty good. But you're not, so don't bother.

Commonly mistake with this support job is the Agility boost you get from this. Fact: Ninja gives just as much Agility (at level 75) as Thief does! Now to smack down some reasons to set Thief as your support job explain why you shouldn't use this as your support job:
Evasion Bonus does nothing for Ranger, who already has an E-rating (caps at 200 at level 75), and foes you usually level on hardly misses, even a thief.
Sneak Attack and Trick Attack doesn't even work with ranged weapon (skills), unless you're planning to Rampage your way through towards 75.
Flee pulling has been an excuse to use Thief as a support job. Planning to pull once every 5 minutes going at a whopping 2000-3000 exp per hour!
Agility boost from this support job has been another excuse. Fact: using Ninja as your support job gives the same agility!
I'm done with this, if anything that's worth using this as a support job is in Sky to Mug the occassional God you fight with your linkshell, but the linkshell leaders will not be happy with that.

Paladin

Dark Knight

See Red Mage.

This could have been interesting. With Last Resort you have a form of Berserk. And Soul Eater adds 10% extra damage to your attacks, with barrage this could mean up to 7 times 10% of your current hp (52%), making galka rangers vicious in a single barrage. But it doesn't work with Ranged Attacks, so don't bother.

Beastmaster

Bard

Beastmaster gives a good Charisma boost, which is practically useless for Rangers. You'll have a hard time charming monsters as well. Aside from charm, you can't even call a pet with a jug and it offers nothing offense and defense-wise.

What? A singing Ranger? What are you, Robin Hood? No, simple as that.
When you're not a main Bard, your songs are only at half strength, you don't have access to the better songs (best "buff" would be Advancing March) and you cannot equip an instrument, weakening the effect even more and restricted to one active song. Again: NO!

Samurai

Ninja

At first glance, an odd choice. Taking another glance, I agree, but couldn't help to try it. You could consider this another support job for damage with a small defensive benefit after level 70. Store TP helps the extra little bit of TP again, and depending on weapon you might save a shot before you're able to throw a weapon skill, increasing your overal damage over time due to the extra weapon skills used. I'm not gonna start with the +strength increase from Hasso, it comes at the cost of melee weapons, as you need to equip a staff, putting a big dent in your ranged accuracy. My personal favourite with a five-shot gun build, but not recommended to use it while leveling.

The standard and all-purpose support job as a Ranger. If there is a support job a ranger must have, it's simply Ninja. Dual Wielding allows you to equip an extra knife/axe, assuming you're using Archer's Knife, Hawker's Knife, Trailer's Kukri, Fransisca or Kriegsbeil, providing an extra stat boost. Utsusemi has two benefits as well: the best form of defense you can get as a Ranger, and with that less holding back your shots, indirectly increasing your damage over time.

Dragoon

Summoner

As a Ranger, your forte is your ranged weapon. Jump is based on your melee weapon. There is one use for this however: Odin's Chamber (Einherjar). By using High Jump you can shed some not-so-precious hate, you can push your damage some more if you're grabbing hate too frequent. For other things it's not too useful.

When this is set as a support job, your summons (pet) are only at half your level/equal to the level of your support job. At low levels, it could be useful as the difference is only minor, but the higher you level the less useful it becomes, if not completely useless.

Corsair

Puppetmaster

If you want to buff your party and deal damage, pack up your ranger and go level Corsair, I mean it. Much like why you shouldn't choose Bard as your support job; the buffs are nowhere as effective as a main Corsair and you're also restricted to one active phantom roll. It's commonly mistaken as well that the Rapid Shot trait from Corsair stacks on top of your natural one as a Ranger, this is not true. Like bard, simply NO!

See Summoner.

Blue Mage

Dancer

See Red Mage.

A popular support job among melees to solo as of late. But rangers are squishy and you're hampered to use abilities during and after each shot, making this not worthwhile to use as you lose more hp than you can restore unless you completely stop shooting.

Scholar

See Red Mage.