As an archer you have to worry about several different things.
Get a Bow
Without a bow you're not an archer but a target. Bows are extremely vulnerable to sunder attempts. Dedicated archers, in particular, are extremely vulnerable to sunder attempts even from folks without any improvements to sunder attempts because most archers don't threaten their areas--and therefore can't make attacks of opportunity--while their bows are readied. So you get a bow made from special materials; I suggest living steel (the metal not the RPG). There doesn't appear to be an immediate equal to D&D 3.5's elvencraft (which simply let a bow function as a quarterstaff), so you're stuck with spiked armor if you don't want to drop your bow to stab a nearby orc. Then get a locked gauntlet or a weapon cord or both. Alternately, and embarrassingly, the Improved Unarmed Strike feat is a thing if you don't want to be all prickly.
It's probably better to just spike up as the bowstaff spell's short duration makes prolonged engagement problematic unless you're not doing anything else with your swift actions.
If the campaign lasts for any length of time that enables your character to develop a reputation, some smartass monster's going to start with your bow and then carve you up when it's gone. So make sure it's never gone.
A bow without arrows is a just a bad fishing pole. You're going to need a lot of arrows. And, unlike the swordsman's sword, all your arrows that hit and half that miss are destroyed. This can be expensive. You can waste your time chasing the ability to make your own arrows or take the Leadership feat and have your followers make them for you (they probably won't be very merry at that prospect, though), but no matter what you're going to need arrows for a variety of situations. There are a lot of different arrows. It's worth getting the basics: standard, bludgeoning, and slashing; and adamantine, cold iron, and silver. You probably won't be able to carry every permutation of these, but you should have 2 combat rounds of ammunition of each of the latter 5 and many, many more standard arrows for goofing off against typical foes and shooting apples from children's heads.
Your biggest advantage over everyone is the range of your weapon. The battle map just isn't big enough to handle the ranges at which you're attacking. You need to control encounter distance, and you do that by having the biggest, fattest, stupid-large Perception bonus you can possibly attain. So get Perception as a class skill, keep it maximized, devote obscene resources to making it bigger, and don't go blind. Anything that improves or protects your vision is solid gold.
The most common type of Perception bonus is the competence bonus. You get this from bracers of the falcon's aim, which if your DM doesn't immediately ban means you can expect the campaign to be extremely challenging. It's dirt cheap, in essence grants the Improved Critical feat for your bow, and grants a +3 competence bonus to Perception checks. You can get a permanent +8 racial bonus to Perception checks by chugging 20,000 gp of demon senses; it's worth the red ears or forked tongue. You can get an insight bonus to Perception checks via the fan-coverted spell pattern recognition. The high-level spell eaglesoul grants a +2 morale bonus to Perception checks versus evil creatures. You can get at least a +10 enhancement bonus to Perception checks with the spell acute senses. In other words, like most of Pathfinder, spellcasting rocks, and being without the Use Magic Device skill means you're boned--get the Use Magic Device skill and buy wands and staffs of spells that aren't in magic items.
There's one item--the third-party major artifact Tsystalor's breastplate--that renders the wearer immune to blindness. In D&D 3.5 this was accomplished by the 3rd-level spell vision of the omniscient eye, but apparently such an effect is far more valuable in Pathfinder. Follow rumors about and go on quests for this item. Almost nothing hurts the archer more than blindness; there are ways around it so you don't have to see, but always being able to see is always much better. The only other way is the 20th-level starsoul extraordinary ability from the sorcerous starsoul bloodline, and that's way too long to wait and way too weird for an archer.
You'll eventually want an item of true seeing (that's not Tsystalor's crazy breastplate). Of course you want truesight goggles--everyone does--, but until you can, the +1 weapon special ability seeking functions as a sort-of workaround.
Get Dispel Magic
A surprising number of spells baffle archery completely. Most of these are spells based around high winds, and usually cast by druids. These spells mean you lose. Heck, the solid fog spell is low-level enough that you could actually see it happen, and you're not using archery in it or through it. Like, at all. So you need to make it go away. If you've a spellcaster on your side that might be his job but try to get your own way of employing an effect like the spell dispel magic, like a wand if you've the skill Use Magic Device or, if you don't and you can afford it, an orb of utter chaos or a spirit blade.
- Although single-target and a competence bonus, the spell hunter's eye grants a +20 to Perception checks and has a 1-minute-per-level duration; that's enough time to cast it, run away, and snipe a fool until he's dead.
- I like the +2 weapon special ability endless ammunition, but almost as good is the +1 weapon special ability conserving, which makes it so your arrows are never wasted; combine with the +4 weapon special ability second chance and your attacks are rarely wasted.
- The +4 weapon special ability nimble shot probably isn't worth it. +4 is a lot of resources to devote to not making a 5-ft. step.