1) SoJ is generally considered a lukewarm card. Its best usage is when paired with a mid-range deck; neither full control, which specializes in late game, nor aggro/shockadin, which favors immediate pressure.
2) The number of avenging wrath in your deck will depend upon your deck style. It fights for a spot among other high-mana cost cards, and it ultimately comes down to personal taste. Some prefer Avenging Wrath, others prefer the more controlled Argent Crusader (4/2 charge divine shield), and yet others prefer (or have access to) legendaries such as The Black Knight and Sylvannas.
3) Our best card draw is Azure Drake. Use two of them. It sounds like you favor control/midrange, which means Divine Favor is not a real option for you. Instead, seek to add a one Lay on Hands to your deck. Good healing, good card advantage.
Equality (2), Aldor Peacekeeper (3), Truesilver Champion (4), and Consecrate (4) are contained in virtually every Paladin deck.
Control decks add Guardian of Kings (7), Lay on Hands (8) and Tirion (8).
Aggro decks add Blessing of Might (1), Divine Favor (3), and occasionally a Blessing of Kings (4).
Midrange blends the two.
All secrets. They can be used sparingly, in certain decks, but they are a trap for new players as they are often inefficient (it basically takes 2 of your cards to deal with 1 of your foe's cards, which is a bad trade).
Blessed Champion. The worst buff in the game. Daydreams about comboing it with two blessing of Mights for a 20 damage swing is just that... a dream.
Holy Wrath. Randomized damage means you can't guarantee killing off a necessary minion. Use Hammer of Wrath instead, if you feel the need to smite.