Healbot - Oradin

Race Tiefling(Kyton-Spawn)
Stats: Cha > Con > Wis > Str > Dex > Int
Classes: Oracle 1 - Paladin (Hospitaler) 11 - Medium 2 - Paladin (Hospitaler) 6
Favored Class: Paladin
Feats:
1) Fey Foundling
3) Healer's Hands
5) Signature Skill (Heal)
7) Skill Focus(Heal)
9) Extra Lay on Hands
11) Selective Channel
13) Psychic Healing
15) Channel Surge

Skills:
Heal, Knowledge(Planes).  Keep these 2 maxed out.  Anything else is secondary.
Class Option Choices
Oracle:
Take the Life mystery with the following revelation - Life Link
Paladin:
Take the following mercies: 3> Shaken, 6> Enfeebled, 9> Injured, 12> Restorative, 15> Amputated
Favored Class Bonus: Tiefling favored class ability - +1 damage healed to yourself with lay on hands.
Divine Bond: Alternate Bond - Agathion Bond.
Medium:
Take the Hierophant Spirit. For your Taboo, follow the paladin code.  This is a no-brainer.  You're a paladin so easy choice.

Putting it all together:
This build is for players that want to heal.  If you are looking for a build that can do something else, this is not the build for you.

For the sake of brevity I am going to be using Character level 15 for what abilities are used, and their effects.  Then I will give extra tips for at lower levels.  I am assuming you have the following relevant stats at level 15:
Wisdom: 14
Charisma: 22 (Base 16, +2 race, +2 levels 4 and 8 increase, +2 item)
Intelligence: 10

Abilities:
Lay On Hands:
This should be used to heal yourself.  It should only be used on someone else if you have no other options available.
Fey Foundling adds 2 HP per die rolled to any magical healing that targets you.  Tiefling favored class bonus heals you an extra hit point per level with lay on hands.  Agathion Bond increases the healing done with lay on hands and spells by (charisma modifier + 1 per 3 levels after 5) So your lay on hands should heal you for (1/2 paladin level)d6 + (2xPaladin Level) + Charisma Modifier. The medium's hierophant spirit gives an extra 2 healed to all healing abilities.  So at level 15 (Paladin 12) you will heal 6d6+ 12 (fey foundling) + 8 (Agathion Bond) + 2 (Hierophant Spirit) + 12 (Tiefling Ability) for a total of 6d6+34 damage to yourself as a swift action.  This will also give you fast healing 3 for 6 rounds thanks to the Injured Mercy.

Heal Skill:
Thanks to Healer's Hands you can use treat deadly wounds as a full round action instead of taking 1 hour, and no longer need to expend uses from a healer's kit for it (as a side benefit whenever you make a DC 30 on heal check you add your ranks in Knowledge(Planes) to the damage healed.  Thanks to the skill unlock at level 15 from signature skill treat deadly wounds heals hit point and ability damage as if the target had rested for 3 days.  At level 15 you should be able to make the DC 30 easily (15 ranks + 2 Wisdom + 6 Skill Focus + 3 Class Skill + 1 Hierophant Spirit for a total of +26).  Total damaged healed by your heal skill will be: 45 (3 days of rest) + 15 (Ranks in Knowledge(planes)) + 2 (Wisdom modifier for beating the treat deadly wounds DC by 5 or more) + 2 (Hierophant spirit) for a total of 64 hit points healed.  This will also return 6 temporary ability damage.  Finally thanks to psychic healing once per day per person, when you use treat deadly wounds it also adds a number of temporary hit points equal to the amount of damaged healed.  meaning a full round action heals 64 damage and provides 64 temporary hit points for an effective healing of 128 hit points.  (As a comparison heal a 6th level cleric spell will return 150 hit points at this level, making this characters heal skill almost as effective as a 6th level spell)

Channel Energy:
Thanks to the hospitaler archetype channel energy no longer costs uses of lay on hands.  You get it exactly the same as a cleric of paladin levels -3.  So you will have 9 uses of channel energy per day that heal 5d6 damage each + 2 from from the Hierophant Spirit + 8 from Agathion Bond so when you use channel energy you will heal allies for 5d6+10 and yourself for 5d6+20 for one use of channel energy or for 2 uses you can increase this by 50% (thanks to channeling surge) for a total of 7d6+15 to allies and 7d6+30 to yourself.

Aura of Healing:
Heals your allies for 1 point of damage per Hit Die as long as they spend a full round within the aura.  Thanks to the hierophant spirit and agathion bond this increases to Hit Dice + 10.  So assuming your allies are the same level you are and just have class hit dice this makes for a free 25 damage healed.  However since allies can only benefit from it once every 24 hours it's of limited use.  The real benefit for this is that allies in the aura automatically stabilize, and are immune to bleed damage.  This buys you time to do real healing.

Notable Spells/level/class:
Oracle:
1) Sanctuary - opponents have to make a will save to target you, whether with spells or with attacks.  This ends if you attack, but since you shouldn't be attacking this is a non-issue.
Medium:
1) Long Arm - increasing your reach by 5 feet means not getting so close to the fighting to heal your allies.
Paladin:
1) Litany of Sloth - Prevent 1 opponent from taking attacks of opportunity for one round.  Useful for getting to someone that needs healed without being hit.
2) Shield Other - the single most important spell in this build. This allows you to absorb half of the damage taken by another character.   Since you are more efficient at healing yourself than other characters this works in your favor.
2) Sacred Bond - Pick an ally, cast touch spells on them at range.  useful for delivering healing spells without being in harms way.

Tactics:
At the beginning of the day choose someone to use the oracle's life link on.  This should be the character with the fewest hit points (preferably a wizard or someone that your really do not want to drop in combat)
If you have warning that a fight is going to break out cast shield other on your meat shield first.  Other wise this should be the first thing you do in combat.

In combat typical actions will be:
Round 1) Move Action to get in touch range of an ally, Standard Action to cast a healing spell
Round 2) Full Round Action, use treat deadly wounds on the ally.

Repeat as needed with other allies.  Use a swift action to heal yourself with lay on hands whenever you want.

The real benefit of this build is the ability to eliminate the need for magical healing overnight or between encounters.  Thanks to your heal skill you can reasonably expect to start every encounter with all allies at full hit points without the need for expending spell slots, class abilities or consumable items.  (Assuming you have at least 2 minutes of down time between encounters that is 20 uses of treat deadly wounds which should be plenty to restore hit points to allies)

Gear:
Magical Gear:
Weapon - Inheritor's Light.  +1 Longsword, any cure spell or lay on hands heals one extra point of damage per die.  If you can't get this your weapon is completely irrelevant.  A mundane club is probably fine.  If you are attacking, something is seriously wrong.
Armor - the heavier and better enchanted the better.  Same with a shield.  Magic Full Plate and a Magic Heavy Steel shield with the best enchantments you can afford are what you are gunning for.
Headband - Anything that increases charisma will improve your healing, your spell casting, and your saves, your number of uses of lay on hands, and your number of uses of channel energy; get a +6 Charisma headband as soon as you can.  Once you have charisma up Wisdom is useful for the heal skill.  Intelligence is useless.  just don't drop it below 10.
Forearms - Bracers of the merciful Knight.  Lay on hands as if you were 4 levels higher.  that's an extra 2d6+4 damage healed to yourself every round.
Belt - Boost Constitution first.  More hit points means you can soak more with Shield Other/Life Link.  Following that Dexterity to boost AC and reflex saves.  Strength is only relevant to keep your load high enough to wear armor.
Ring - Ring of Freind Shield.  This gives you a 3rd person that you protect by absorbing damage for them.  Be careful though.  Take damage for too many allies and you may not be able to keep up in particualry deadly encounters.

Mundane Gear:
Masterwork Healer's kit - You don't care about the uses from the kit.  What we do want is the +2 to heal skill checks.  at level 15 this gets us to +28, so you only fail the DC 30 on a roll of 1.

I'm sure there is more gear out there that will help.  But realistically you are looking to do three things (in this order) Boost Charisma, Boost Lay on Hands, Boost Heal skill, Boost Constitution.