Ok, so the first thing you need to do when making a character in the character builder, is make sure you choose the "Neverwinter Campaign" as the first option. This will restrict you to Essentials choices that are legal for your Encounters game. It will also save you a lot of confusion.
Secondly, when choosing powers as you level up, try to balance between healing, debuffing, and buffing. Look at how many heal powers you already have. Is it enough? Is the party dropping dead a lot or are you often left with healing powers you never use? If you don't need healing powers, next look at enemy debuffing powers (penalties to enemies) or ally buffing powers. Temporary hit points are always excellent because they mitigate incoming damage, making your job of keeping the party alive much easier. Bonuses to attacks for allies and penalties to attacks for enemies are likewise very good options, with a preference going towards bonuses to hit because everyone in the party gains a benefit from everyone else hitting more often.
The other thing you need to consider is choosing melee powers with the 'weapon' keyword in them. This shouldn't be a problem as long as you select the right campaign model, but in case you don't or you accidentally click, "Show more options", keep this in mind. As for implements, you can completely ignore them if you want.
The other thing you want to consider is Constitution-based powers. This is what is known as a 'rider'. It's your secondary ability score (the second highest) and so it affects things in some of your powers. If you can, try to choose powers that give a benefit based on your Constitution score, as long as the above considerations are taking into account first.
Now, I went with a sun priest for you because they're one of the best choices. You get lots of save granting options, healing boost, bonuses to useful things like death saves (remembering that the +2 to death saves means that if you roll an 18 or higher, you can spend a healing surge and pop back up), and good all-round party support without being a totally focused healer-monkey.
Personally I would've gone 20 Wisdom and I would've dumped Charisma, but that's not what you wanted. So the 12 in Intelligence gives you a Reflex bonus and increases your Intelligence-based skill checks. The reason I didn't go Dexterity was because I went with Battlewise which uses your Wisdom for your Initiative. Going first matters a lot in these games and as a leader, you want to try and debuff/buff as soon and as often as possible.
Now, you got Perception as a trained skill like you wished, and I gave you a 'special' weapon (a triple-headed flail) like you wanted; the reason for choosing this was that it's a +3 to hit proficiency weapon and does nice damage. Technically the weapon choice isn't that great because of a lack of feat support, but that won't matter for you until around 10th level and beyond and by then, there should be options for you (hopefully).
I also gave him Netherese as a language choice. This was a flavour thing since he's a Sun Domain cleric and Netheril has returned from the plane of shadow, I figure you could roleplay some connection there. The Aglarond background was to gain Perception as a trained skill (with a +1 no less!) and also gives Elven as a language. Don't know how that fits in with Neverwinter but hey, I'm sure you can think of something
So, hopefully this has helped and you enjoy the character:
level 1
Human, Warpriest
Human Power Selection: Heroic Effort
Background: Aglarond (Aglarond Benefit)
FINAL ABILITY SCORES
Str 10, Con 16, Dex 10, Int 12, Wis 18, Cha 10.
STARTING ABILITY SCORES
Str 10, Con 16, Dex 10, Int 12, Wis 16, Cha 10.
AC: 18 Fort: 15 Reflex: 14 Will: 16
HP: 28 Surges: 10 Surge Value: 7
TRAINED SKILLS
Perception +10, Religion +6, Insight +9, Heal +9, Arcana +6
UNTRAINED SKILLS
Acrobatics -3, Bluff, Diplomacy, Dungeoneering +4, Endurance, History +1, Intimidate, Nature +4, Stealth -3, Streetwise, Thievery -3, Athletics -3
FEATS
Human: Battlewise
Level 1: Weapon Proficiency (Triple-headed flail)
POWERS
Ordained Priest Starting Feature: Smiting Symbol
Warpriest daily 1: Nimbus of Holy Shielding
ITEMS
Triple-headed flail, Heavy Shield, Chainmail
