Below is my opinion of the different range weapons and how I use them. Please provide any additional insights or alternative methods you prefer. Thanks
Longbow- Primarily for single targets and requires use of Hunter's Shot and Rapid Fire to be truly effective. Point Blank Shot is incredibly useful and Barrage is a lot of fun. Long Range Shot is kind of blah due to damage shifting with range and the frequency of close combat compared to fights at longer ranges.
I prefer LB for most of my PVE simply because I like having knockback ready and rapid fire is great for killing a target quickly. I switch to SB when I'm in restricted terrain though due to LRS having crappy in close DPS.
Shortbow- Crossfire is nice because it does good DPS without having to worry about clicking any other button. Poison Volley seems ok for a little added damage but I only use infrequently. Quickshot I dislike because I don't really kite and I hate getting knocked backwards, I can see how someone who prefers kiting would love this skill though. Crippling shot and Dazing shot are both good for a little extra oomph against a target but the long reload on Dazing shot reduces it's appeal.
I use SB when I'm in close quarters and that's about it. This allows me to watch what's going on around me without having to hit any other attacks due to crossfires DPS. I mainly use this against single targets and switch to Axe/off-hand for multiple bad guys.
Greatsword- This weapon is good when you are fighting in a group and pull agro from time to time. Primarily a single target weapon the length of the blade though can give you some additional damage against mobs packed tightly together. Maul is a good skill although it requires constant reapplication. Swoop is fun but has a moderately long refresh and I prefer to use it for the combo bonus. Counterattack is a very nice defensive skill and is great if you need to avoid an attack while heals land. Hilt Bash is also a good skill to add something extra in a tight fight.
I like GS when I need to be in melee range and want a little extra defense. This weapon isn't suited for full time use however it shines in select engagements.
Sword- The 1hd sword seems designed for someone that likes to flit in and out of a fight. The skills have you leap or jump back which can allow you to evade incoming damage if timed properly. Unfortunately I don't really like this style of fighting for PVE so I rarely use this weapon.
Axe (main hand)- This is my favorite weapon for use against multiple mobs. Ricochet hits several opponents and is a good auto attack.Splitblade is situational but can add some extra damage once everything is agroed. Winter's Bite provides some damage mitigation and boost DPS a little.
Axe (off hand)- Continuing the multiple opponent theme Path of Scars will hit multiple mobs going away and coming back to you when your axe is thrown. Whirling Defense adds some mitigation while dishing damage to multiple opponents.
All in all the Axe is a great weapon when you are fighting groups of foes. Both main and off hand provide excellent options when facing more than one target.
Dagger- Single target off hand weapon, pairs well with sword.
Torch- Provides a good single target dot and an AE dot. Blends well with Axe or sword.
Warhorn- Useful in a group situation to provide three buffs to you and your allies. Has a fun single target attack with Hunter's Call. Nothing like a swarm of hawks pecking your foe to death.
Harpoon gun- My preferred weapon in the water. Good against single and multiple targets. This weapon is more about DPS and less about defense. Piranha is especially fun to use.
Spear- The defensive water weapon. This is a good weapon when fighting many targets where you frequently pull agro.
Longbow/shortbow weapon swap is obvious. What weapon swap do you use for melee weapons? I like GS swap with LS/dagger. For PvE, I'll mostly stay on GS, use the leap to close the gap and will swap when I use all my abilities so I can use the viper ability. Then switch back to GS as soon as swap cooldown is up and use abilities again, rinse wash and repeat.
I tend to use LB/SB, but I use the LS plus war horn in place of the SB in places like Orr where I need the speed boost to move through the zone. Too bad Anet doesn't allow more weapon swaps (GW1 allowed 4 afterall).