One thing that's not essential, but darn nice to have if you're making Neapolitan-style pizza is Italian flour. The kind you most often see recommended is called "00" flour. As to what exactly that is, there seems to be quite a bit of confusion. Search around the web a little and you can find all kinds of animated discourse on the subject:

It's HIGH-gluten flour specifically made for pizza.

No, it's LOW-gluten flour that's used for pastry.

No, it's flour that's only used for bread!

No, it's flour that CAN'T be used for bread!

I'll do my best to settle this little kerfuffle, because it is a touch complicated. First off, Italian flour makers don't classify flours in terms of their gluten content. Rather, they classify them by grind. Type "2" flour is the coarsest grind, what we in the US might call a "meal". Types "1" and "0" are medium grinds for bread flour. Type "00" is the finest grind, and it's used for both bread (including pizza) and pastry.

Obviously any kind of wheat, hard or soft, high gluten or low gluten, can be ground to any of these degrees. Which means that different "00" flours can have any of a number of baking characteristics (Italian commercial bakers have many many different kinds of "00" to choose from). In general though, the "00" flour you see in specialty stores is roughly equivalent to our own all-purpose flour. It's fairly high in gluten, and good for a lot of things.

So then if it's high in gluten, why do some pizza makers substitute extremely LOW gluten flour for Italian "00" flour in their pizza crust recipes? The answer is that not all gluten is created equal. Some varieties of wheat contain gluten that is both hard and springy (like our own hard red summer wheat), and make very elastic doughs. Other types contain gluten that's hard but not springy (Italian durum for example) which produce doughs that are firm but not very elastic. Most Italian flours are of the latter variety, which is why most real Italian pizza makers don't do this with their dough, but instead prefer to stretch their pizzas into shape.

What does it all mean? It means that Italian flour has "bite" but not "chew". American high-gluten flour has both "bite" and "chew", but that's not necessarily a good thing, depending on who you talk to. Some American pizza makers, hoping to more closely approximate a Neapolitan-style pizza, opt to eliminate the "chew" of American flour by employing an extremely low gluten flour, sacrificing the "bite" in the process. It's a trade-off that some people really like, for instance me, though I definintely opt for the genuine article when I can get it.

Hope than makes sense.