Well, if you want an aggressive deck, you should cut down on the expensive creatures. Having 1 or 2 in a deck is okay, but by far the most important creatures in aggro are the 1-, 2-, and 3-drops. You'll want creatures like
Lightning Mauler,
Diregraf Ghoul,
Mogg Flunkies,
Gore-House Chainwalker, et cetera. One- and two-mana creatures are your bread and butter. Three-mana creatures should have some sort of effect to get your army through, evasive, or just be really large for the cost. A good example is
Pyreheart Wolf, which makes everyone much harder to block. The expensive creatures are there to punch through damage if the opponent manages to stall your attack. Only have 1-3 of them, perhaps 4 if they're 4-mana creatures.
Now for spells. Aggro loves
burn. Aggro loves black creature removal (
Tragic Slip). Aggro loves power-boosting Equipment like
Civic Saber or
Bonesplitter. Aggro does not love
Damnation. Board wipes are your worst enemy, so you probably don't want to have them in your hand.
Whispersilk Cloak is good for getting damage through, but the typical aggro deck wants to have a lot of creatures attacking, not just one. Thus, global effects tend to be stronger than one-creature buffs. For a few enchantments to try, if they're more your thing,
Volcanic Strength (+2/+2, mountainwalk) on a 2-toughness creature will be
terror for a red deck.
Madcap Skills makes one guy very powerful, but does not boost toughness, so it's best on a first-strike creature. I like Rakdos's Return. It gives you a bit of reach to get through after your attack has been stalled by bigger creatures.
Another good thing to add to your deck is some card advantage. Drawing cards is one of the most powerful things you can do in Magic. Black is very good at drawing cards. Spells like
Sign in Blood and enchantments like
Underworld Connections allow you to trade your life for extra cards. Remember, the only point of damage that matters in the end is the last one. Your life total is a resource just like the cards in your hand or your mana pool. Use it wisely.
Alternatively, try to get a couple more
Rakdos, Lord of Riots. You could build around him to let you cast big creatures quickly. This would probably involve casting small creatures that can get past blockers early to land Rakdos, like
Tormented Soul or
Goblin Fireslinger. Then, Rakdos will take a chunk of life out of your opponent and the two-mana Dragons will follow. The downside to this strategy, of course, is that you need to have Rakdos out. Having mana-producing artifacts will let you cast your big stuff earlier, and let you play more like a green ramp deck with removal.