I'm not the best HotS player, but I'm not the worst. Yell at me if I say something stupid. "If you srike me down I'll become mo-..." yadda yadda etc.
These builds are general ideas and I chose certain talents on the fly depending on team comp and maps.

At the time of this writing I've played 11 QMs with Johanna, so this guide is incomplete and I will update along the way.

Also this is my first guide and I'm fairly certain every HotS player has figured all this out already. But whatever, it's slow at work and I just got paid writing up this build. And I love her. And this game. And you. <3

Queen of Chase
This build is great at chasing people down and taking on creep. More importantly, at level 7 you take Conviction, allowing you to pursue heroes effectively. In my opinion anyway.

Survivability
This build has ridiculous sustain. I only go this route if I have a team that can follow up behind me and engage. Feel free to jump right in and engage, just remember to abuse the D.

Here is the basic idea of how to play Johanna:

Use the W to pull enemies into you, then use the Q to slow them down if they turn tail.
Use the E to disrupt characters that love to auto-attack(Raynor/Valla/Illidan/etc.)
Use the D to engage, disengage, or protect yourself. Best used if the enemy team has ways to displace or stun you, because you become UNSTOPPABLE for 4 seconds after it's activated. This stops stuns and displacements. But you can't use it to break out of them.

Now let's take an in depth look at her talents:

Reinforce I almost always go with Reinforce. This allows you some extra sustain as you jump into fights, suck people in, and smack them with your shield. It doesn't trigger off of your heroic ability, so as you land be sure to slam the W and then land that Q.

Knight Takes Pawn Take this talent if you want to focus on painting the map. It's a good talent, but I feel like Johanna's skills are put better use elsewhere rather than taking camps. If you don't have a Gazlowe/Murky/Brightwing/etc. to easily take camps, this is a good choice. I still think you'll get more bang for your buck out of Reinforce.

As for Righteous Smash and Regeneration Master, they may have their uses but I didn't find either to be good as the first two.

Laws of Hope Absolutely gorgeous talent, this makes Johanna even more tanky. Be sure to use this early on in team fights though, it's 5% of your max health every second for 4 seconds. So the 20% comes slowly, but it makes her sustain amazing. The extra passive health regen is also nice. It's hard to notice, but it's there.

Amplified Healing is always going to be good to take when you have a support or two. If you have a Brightwing sticking on you like glue it might be better to take this rather than Laws of Hope.

Roar is nice, but I still think the extra sustain from Laws of Hope/Amplified Healing is better than any extra damage this would provide.

Eternal Retaliation is good too, especially when you're going to be the one constantly engaging team fights. But again, you're missing out on some great sustain if you go this route.

Most of you are probably thinking "Battle Momentum! Battle Momentum!"
But let me try an persuade you to one of my favorite Johanna talents:

Conviction This will increase your movement speed slightly(25%) for one second. "Only one second?!" Yes. Only one second. However, think about it. This is going to allow you to catch up with most heroes that are running from you. As soon as you pop your Condemn, prepare the Q and hopefully you have a team following up behind you to confirm the kill. I love this talent, I've been able to catch so many players this way.

The Crusade Marches On I recommend this talent if you don't go for Conviction. Why? Because Battle Momentum doesn't reduce the cooldown on your trait, this does. Johanna's trait is hilariously amazing.

Sins Exposed seems very weak to me. Avoid. Or maybe take it and prove me wrong, I don't know. I didn't think the damage was worth missing out on these other amazing talents.

You can't go wrong here. Well, not entirely.

Falling Sword This is going to be your best engage option with Johanna. Jump in, slam down, pop the W, aim the Q, prepare the D, win. Aim for weaker heroes with this, your goal by jumping in with this ultimate is to disrupt the enemy's formation and throw their ideas of combos out the window. This will allow your team to commit to a fight by jumping on your enemy's ranged or support heroes. It pretty much says "Hi, my name is Johanna. I've come from the heavens and I'm here to make sure you go NO WHERE."

Blessed Shield This is going to give you a TON of interrupt options with Johanna. See a Valla spinning? BLESSED SHIELD. See Lili's cups of a thousand eff yous? BLESSED SHIELD. ETC throwing a dance party? BLESSED SHIELD. And so forth.

That being said, you can interrupt all of this with your W as well. That's why I normally go with Falling Sword. BLESSED SHIELD has the added benefit of bouncing to nearby players and stunning them for a shorter duration than the first person hit.

Before you pick Burning Rage for the extra damage, let me persuade you to check out these other options. Remember, I think a good Johanna is less about the damage and more about disrupting and surviving.

Hold Your Ground Like her D? Yea you do. Enemy team bursting down the shield you get from it? !@#$ them, take this and laugh.

Subdue I take this talent a LOT. Why? It increases your Q slow speed by 20% and the duration by 1 second. This allows you to slow your opponent down to a crawl for THREE seconds. Precious time in which they'll **** their pants because they can't escape your flail.

Burning Rage This is a highly sought after Johanna talent. It gives her some extra damage which she is desperately lacking. Take it if your team is falling behind on kills, then hop into team fights pop the D and laugh at your now flaming foes.

Don't take Spell Shield. I just don't see the need on a character already so tanky.

Blessed Hammer For when you need to dish out some punishment with your W. This drastically increases Johanna's damage. Don't get me wrong though, this doesn't maker her super crazy good with damage. But now you can help pick off heroes that are nearly dead.

Fanaticism Still enjoying that sweet sweet D of Johanna? Yeaeaaaa you are. Take this if the enemy team is focusing you and laugh as you disengage HARD.

Imposing Presence is always good to take against a Valla/Illidan/Tychus/Other heroes that rely on high attack speeds.

Holy Renewal the healing from this doesn't seem to increase her sustain any higher than it already is. If you take this, just remember you need to hit PLAYERS for the healing effect.

Heaven's Fury YES. All the yes. It's just fun okay? I don't have reasoning behind this. I didn't feel like the cooldown reduction was enough to be able to use Falling Sword twice in one engage(even hitting 4 or 5 players.) But the extra damage is nice.

Radiating Faith This allows your shield to hit 5 enemy players maximum. That's pretty good. Decent damage too. Solid choice. No more comments.

Indestructible EVEN MORE OF ALL THE YES! Only take if you're dying a lot/getting focused. It's hysterical to watch enemies chase you down, and just when they think they have you BOOM SHIELD FOR MAX HEALTH WHAT?! That being said, if you're with a good team and you're playing her right, you won't need this.

Storm Shield for squishy teammates.

Thanks for reading! I'll continue to update this as I play more Johanna. I really enjoy this hero and I think she's the perfect tank and fight engaging character.