I started this deck as something cheap to play with friends of mine that didn't have the stomach to cough up hundreds for a deck of cards. But as time went, I couldn't help myself. I think this brings the idea of a tribal deck back into focus for modern, only time will tell.
Like any aggro deck, overwhelming your opponent is key. Your most valuable knight is Knight Exemplar. If you have a few mana and 1 on these in your starting hand, keep it. The next most important knight has to be Mirran Crusader. His DS will do so much damage to your opponent that they will be forced to deal with him.
What I try to accomplish in most games is making 2 Knight Exemplars and having their passives pump one another (and every other knight on the field). This can be achieved by use of Phantasmal Image. These cards should typically be used to make copies of either Knight Exemplar or Mirran Crusader. Once your creatures are indestructible, there isn't a whole lot your opponent can do to stop them. The deck runs 30 knights, and with a good mana base, you should always have a hand full of creatures to continue the beat-down. Most of the time, you should win by turn 5 or 6.
Burn decks tend to be challenging, but not impossible. Use the knights that give lifelink as much as possible (Fiendslayer Paladin and Knight of Meadowgrain). A good control deck can also be annoying, so be sure to play around counters and use Path to Exile, Silence, Torpor Orb, and Oblivion Ring to stop combo decks like Grixis Twin.
This is the general idea of the deck. I have seen a few tribal knights decks and have been very disappointed. This is how to build a Knight deck. Please post any questions or comments you might have.