Just so I'm clear:

1. You pay the resources listed on the card (including extra if you don't have enough loyalty icons in play) as if you were playing the card face-up, even though you're playing it face-down as a Development?

2. You can play any type of card (unit, support, tactic, quest) as a Development?

3. If a card's cost is 0 (like Empire's Demoralize, or an "X" cost card, or some quests), then you get the Development for free?

Jaron95 said:

1. No. You don't have to pay resources to play Developments. They are free of cost.

2. Yes.

3. Developments are always free of cost.

Some remarks:
- Unless you have a card effect that lets you do otherwise, you can only play one development per turn.
- Never show to your opponent the card you're playing as a development.
- Developments can be turned face up later in the game through some card effects.

Did you watch the video tutorial ? It is very well done and it helped me teach the basics of the game. In one of the sections they explain how developments work. Here's the link:

www.fantasyflightgames.com/edge_minisite_sec.asp

Holy crap. I'm glad I asked! Thanks.

Quick question (not able to view tutorial, grrr) can you subsequently use developments by flipping face up as if a card in your hand? Or, barring the use of other effects, is the development "fixed" as such?

Without the use of card effects, once you play a development you can't perform any actions with it.

Think of a developement as a discard. It's basically just put into the zone you want. Based upon face up cards in these zones, the developments allow you to do other things.

Like has been mentioned, you may have cards that allow you to use/turn the development face-up.