Our group just began a new campaign yesterday, and for the second time in 3e I'm playing the party cleric -- the first time was actually as an NPC I'd created while one of our players was out of town. Much as my esteemed colleagues have already remarked several times in their posts, clerics are fantastic in 3e. IMO, they may well be the most versatile and playable class under the new rules, so NEVER complain about playing one again

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Take the time to review all of the Domains available for the various Greyhawk deities who allow NG or LG clerics, then choose. Even though you are currently leaning towards Heironeous (a fine choice) you may still want to consider other options.
If you go with a cleric who is capable in combat, the previous advice posted herein is sound. INT and DEX will be your least important attributes, buy heavy armor and/or a shield, and concentrate on deities whose Domains work well for battle priests:
St. Cuthbert -- as Destruction as one of his Domains
Corellon Larethian -- offers the War Domain, and if you choose to be an elf this is the way to go. This was the path I followed for my NPC healer, and it was absolutely fantastic!
Kord -- Supplements Strength with the Luck Domain (if I recall),
I decided to play my most recent cleric a bit differently, and limited his melee combat ability in favor of magic, guile and stealth. If you choose this less common path, I suggest making a halfling or gnome priest of Boccob, Fharlangan or Olidimarra (sp?). Boost your DEX at the expense of STR, equip the PC with ranged weapons and light armor, and choose entirely different Domains. Before designing this character, I solicited commentray from other Board members and here are the Domains most recommended:
Luck; Trickery; Travel; Magic; and Celerity which is a Prestige Class Domain listed in Defenders of the Faith.
There's no question, though, that choosing Domains (and a corresponding deity) takes precedence over feats and skills. The feats and skills you select will likely compliment your Domains and battle prowess.