You've put together a pretty tall order. Paladins are probably the least suited class for archery because of several factors:
1. Their best combat ability--smite evil--only works with melee weapons
2. They don't get any bonus feats and archery can be a fairly feat intensive path to take.
3. Archers need strength to do damage, dex to hit, and constitution to stay alive; paladins need wisdom and charisma to make use of their abilities.
So, single classed paladin is probably not a good plan.
Now, there are several ways you could keep the concept of a holy warrior using a bow instead of a sword but make it work better than single classed paladin:
1. Ranger 4/Paladin 6/Fighter 4/Wild Plains Outrider 2
Feats: Devoted Tracker (Complete Adventurer), Point Blank Shot, Precise Shot, Rapid Shot (ranger bonus), Mounted Combat, Mounted Archery, Track (ranger bonus), Weapon Focus: composite longbow, weapon specialization: composite longbow, power attack, divine might--if human, add Improved Precise Shot.
That gives you a really tough mount--try to get your DM to go for a giant eagle or pegasus and lets you do the mounted archery thing. Divine Might is about the only synergy you'll get from your paladin levels other than the mount but it should work OK. (And with power attack, smite evil and divine might, you can melee acceptably as well).
Stats: Str 18, Dex 18 (+4 level), Con 16, Int 9, Wis 12, Cha 16
Important items: belt of giant strength (+4), holy mighty [+6] composite longbow, gloves of dexterity +4, greater bracers of archery, cloak of charisma +4, vest of resistance, celestial armor or mithral chain shirt, a halfway decent melee weapon (perhaps a +1 sacred ghost touch greatsword), and a quiver of Ehlonna.
Other possibilities:
A. Non-mounted archer: Ranger 12/Paladin 4
Feats: Point Blank Shot, Precise Shot, Rapid Shot (ranger), Track (Ranger), Manyshot (ranger), Improved Precise Shot (ranger), Power Attack, Divine Might, Improved Rapid Shot, Improved Critical (composite longbow) or Favored Critical, and one of the following: Weapon Focus, Quickdraw, or Favored Power Attack.
Stats and equipment: as above, but you might want to sacrifice the greater bracers of archery for lesser bracers of archery and a good periapt of wisdom. As a 12th level ranger, a 16+ wisdom will give you bonus 3rd level spells. Since the character won't have as many options for avoiding melee, you may want to buy a magic buckler and use a longsword, battle axe, or warhammer as your melee weapon--that way you have the option of the buckler's AC bonus or two handed power attack damage.
This character could make a very convincing demon or undead hunter with favored enemy evil outsiders or undead.
B. A chaotic option: Ranger 2/Fighter 4/Holy Liberator 10
Feats: Iron Will, Weapon Focus longbow, Point Blank Shot, Precise Shot, Rapid Shot (ranger), Track (ranger), weapon specialization: longbow, manyshot, improved rapid shot, improved critical: composite longbow OR favored critical, improved precise shot, and either Quickdraw or Power Attack
Stats and equipment: as ranger/paladin.
C. Another set of possibilities: Following an archer god only
Ranger 6/Pious Templar 10
Ranger 2/Fighter 4/Pious Templar 10
Ranger 2/Paladin 4/Pious Templar 10
Ranger 2/Paladin 2/Fighter 2/Pious Templar 10
Fighter 2/Cleric 4 (war domain)/Pious Templar 10
D. Another set of possibilities if you don't mind being dumb or are pursuing an option that doesn't require a high wisdom: Wood Elf. For the first suggestion, you'd have to drop the paladin levels down to 5 in order to avoid an xp penalty but a third level of wild plains outrider is a good option. For option C, you'd need to pick one of the ranger options rather than fighter/cleric as your route to pious templar.
Possible stat arrangements:
Str 20 (+2 level), Dex 20 (+2 level), Con 10 (very risky, but you may be able to stay out of danger), Int 7, Wis 16, Cha 16
This combo works best for builds that give decent spellcasting--pious templar 10, holy liberator 10, ranger 12, etc.
Str 20 (+2 lvl), dex 20 (+2 lvl), Con 14, Int 10, Wis 9, Cha 16.
This combo works best for a build like the first one I suggested which give very little spellcasting.
Str 20 (+2 lvl), dex 20 (+2 lvl), Con 14, Int 10, Wis 16, Cha 9
This build works well in any combination that doesn't grant Divine Grace such as Ranger 6/Pious Templar 10, Cleric 2/Ranger (or fighter 4)/Pious Templar 10, etc.
Hope that helps.