how to heal in arenas as paladin

I don't have high rating so if you came to learn from the best just goole a bit more.
All I can tell about it is how to heal when you want to start doing it properly.

My major problem first was the gear. Healing in PvE gear is a bit suicidal as you overheal too much, have a huge mana pool which is useless when a priest uses mana burn and you simply can't stay alive long enough to do your job: keep yourself alive and heal others. In this specific order.

Gear problem: you need resilience. You don't want to be critted as if your hp drops bellow 30% you are dead (well, after the bubble which is mapped on the button you almost never press in PvE). If you want gear, do some BG-s first. Get the gear from Wintergrasp. You shuold understand that this game basically about having the proper gear for your task. Having full hateful gear basically turns the tables. Get items with resilience for all the remaining gear slots. Until you have it don't expect doing ok in arenas.

Talent: even though the best ranked healer paladins have full holy talent there are couple of other ways to reach our goal: stay alive. Dead healer paladin means the end of the match. As I switched to tank talents I have much better survavibility and arena rating got better and I have more fun. It also gives couple of other options to get control over enemies. If you think you can act as healer with retri talents be sure you never will be forced to heal for more than 5-10 seconds.

How to play? Don't let you or your team mate's hp drop below 50%. Kill the healer. CC only when he is low on hp as you want him/her stop healing while you and your dps mate doing some burst damage. You have stuns, use them. Communicate what you do and what you expect and when. You need to say to your dps if he want to go out of range/sight when he is on low hp thats a huge risk. Do it when the enemy flee and not when your heal fails because of the range. If he wants to finish someone thats a big concern if he has low hp too as you might get silenced and the hunted can turn to be the hunter.

How to communicate? Be nice to your team mate. Uncontrolable rage, blamestorm, screaming certainly won't help. After a match lost think first about your failures. He/she sure knows when you made your mistakes, ask him/her. In fact your dps will exactly know when he/she expected a heal which you failed to deliver.

There is an old PvE rule: "if the tank dies thats the healer's fault, if the healer dies thats the tank's fault, if dps dies that the dps's fault".
In PvP it sounds like this: "if the dps dies, that the healer's fault. If the healer dies, that's the healer's fault".