I've recently gotten back into Magic after a 20 year hiatus, having reconnected with an old friend who is *massively* into MTG. So I've spent a few hundred dollars on the Tarkir block, and picked up a few other cards here and there.

I want to build a deck to play against my friend that's got a fighting chance, so I figured the best way to do it is convince him to build within the Standard format. I can't run out and spend $$$ on lots of 4-of's etc (although I have done that some), so my inventory is very limited.

So with what I have, figured it'd be fun to go for a dragon deck:
https://deckbox.org/sets/965991

This is the deck I've been trying to massage to make good enough to beat my friend, to no avail. Last night he whipped out 2 Siege Rhinos, pumped them, and came back from 3 life to win the game. ;)

Anyway, any constructive criticism/help would be much appreciated. Here's my inventory:

http://deckbox.org/sets/947022

Given that this is for casual play, could you give us some more guidance on what your friend runs?

At first glance at your build has far too many 1-off cards that will lead to some rather serious inefficiencies in play. Further, the payoff you're getting from running blue is marginal at best. Sure Sarkhan Unbroken is fun and all, but in order to go messing with the mana-base I'd suggest having more of a payoff in blue.