I'm a war wizard who likes to buff up front line characters with Fly or Haste (both Concentration spells).   If  I give an allied character a book with the spell glyph to cast Fly on the bearer, and have last until the end of its full duration, and then can I cast a different Concentration spell like Animate Objects without having the Fly spell fail. 

I'm wondering if a Cleric with Divine Intervention can use this to get an instant concentration-free spell.

Eg. Divine Intervention -> Glyph of Warding -> Spirit Guardians

The uncertainty is here:

Spell Glyph. You can store a prepared spell of level 3 or lower in the glyph by casting it as part of creating the glyph. The spell must target a single creature or an area. The spell being stored has no immediate effect when cast in this way.

Would this mean you need to use an additional Magic action to cast Spirit Guardians when 'storing' it in the instantly created Glyph of Warding?

That's kinda broken, but correct. You also don't need to provide the costly component for Glyph of Warding as specified in Divine Intervention.

Don't forget this very important limitation:
" If the surface or object is moved more than 10 feet from where you cast this spell, the glyph is broken, and the spell ends without being triggered."

So if you cast the spell in a book and give the book to the fighter, he has to open the book before moving more than 10ft .

If the surface or object is moved more than 10 feet from where you cast this spell, the glyph is broken, and the spell ends without being triggered.

You can do two things to overcome this.

1. Extra dimension method: You cast the spell while touching the object in the bag of holding/haver sack etc.. To trigger the glyph a creature need only reach into the bag of holding and uncork/open the glyphed object.
Discuss with your DM prior to doing this.

2. Genie Warlock (self only). You need to have at least 13 CHA and a level in Genie Warlock for 5e 2014 rules or 3 levels if using 2024 rules.
You cast glyphs while inside your Genie's Vessel - layering it on top of each other. The trigger can be the next time you step in the location with your fingers crossed or something. When the fighting starts you use an action to super-buff yourself and a bonus action to re-appear.

I saw a joke video saying that the wizard had a spellbook inscribed with Glyphs of Warding written in it for every long rest since level 5. They claimed it had enough magic potential to level a city! Is this even possible if it only affects a 10ft sphere?

Quote from KayinKrueger >>

I saw a joke video saying that the wizard had a spellbook inscribed with Glyphs of Warding written in it for every long rest since level 5. They claimed it had enough magic potential to level a city! Is this even possible if it only affects a 10ft sphere?

It seems pretty clear that whoever said that was not speaking literally.

However, were we to take that claim at face value, there are several reasons it wouldn't work, including:

1. The damage, while enormous, would be contained with a 20-foot radius sphere, and cities are generally considerably larger than that;
2. The damage only affects creatures, not objects, and objects are traditionally an important part of a city;
3. There is a general rule stating that the same spell cannot be applied more than once to the same target at the same time, so the book can't have more than one glyph on it at a time anyway.

I just find it annoying that you can’t move the object after you cast the spell. 

why can’t I have a Nuke in my book :(

This spell costs 200 gp, equivelent to casting Summon Beasts. Now in the common scenario the Big bad put 10 of these in the empty hallway to his chamber, that isn't a problem, but this is pretty expensive for a player (unless your DM is flooding you with money, or you are just at a high level in which case feel free to go crazy).

This spell seems like it will find more use on the DM's side of the DM screen than the player's side of the DM screen.  

Actually, it says the glyph can only cover a 10 ft diamater, not that the spell is limited to that space. That would indicate the casting point is the only limitation of distance, the spells actual distance would still apply. As far as Number 3, would each page not be a seperate object to inscribe a glyph? Now depending on the spells put in the glyphs, I would agree with number 2, UNLESS that was there intention, in wich case shatter and the like do exist.

Quote from FatherSalem >>

Actually, it says the glyph can only cover a 10 ft diamater, not that the spell is limited to that space. That would indicate the casting point is the only limitation of distance, the spells actual distance would still apply. As far as Number 3, would each page not be a seperate object to inscribe a glyph? Now depending on the spells put in the glyphs, I would agree with number 2, UNLESS that was there intention, in wich case shatter and the like do exist.

Ah, I was thinking about it from the perspective of using the explosive version of the glyph, not the version that casts a spell when triggered. However, since only level 3 or lower spells can be used for this, I don't think you're going to find one that can level an entire city. Even if you cast it many, many times, Fireball for instance still only has a damage radius of 20 feet, so you're just setting fire to the same 20-foot-radius sphere over and over again.

As for using individual pages in a book as separate objects, I think that's a big stretch given the requirements in the first paragraph of the spell, but some DMs might allow it.

Also keep in mind that if you up-cast it, you can put an equal level spell in the glyph, so it can get pretty crazy in that sense too. I do believe leveling an entire city using RAW is a huge stretch, but with the right creativity of spells, and using the combo spell ruling within the DMG, it could be possible.