1. As I said before, 18 lands! Get the most value out of landfall AND multikicker. 19 might even work
2. Quicksand is common. Beware for all your weenies. Or just blow them out with a good pump spell. READ Quicksand carefully and try to remember your opponent has it in their pile of lands. If your opponent stacks all his/her lands together, make him/her spread them apart so you can clearly see each one.
3. Equipment are great, just don't stuff your deck full of them. You want around 16 creature spells. Maybe 14 if you're going creature light. Just don't dip too much into your Quests, Equipment, and Enchantments -- having good creature density is majorly important.
4. Don't run all your tapped lands just because you have them. I would avoid ability-lands that aren't in your colors.
5. Feel free to maindeck Goblin Ruinblaster or other nonbasic land hate. No doubt you'll want to get rid of manlands and all the other crazy things like Valakut. There are tons of nonbasics in the two sets combined.
6. I almost want to say having one Naturalize effect maindeck might not be a bad idea... but you probably still want to keep it in the sideboard. But if it's on a Tuktuk Scrapper or a Mold Shambler or something, that's fine. At least that's a creature.
7. Zendikons are something to watch out for. This is why I think enchantment hate might be maindeckable. Prepare for all kinds of random creatures to come out and start swinging when you least expect it.
8. Cunning Sparkmage is retarded. Can I just say that?
9. Do not play Bull Rush. It is terrible.
10. Look at your bombs. Look at your removal. Try to maximize these. And then worry about colors, curve, and mana fixing. Have fun with it.
11. Ask your friends for help. It's a Prerelease. It's relaxed. You can even ask random people. They're going to be excited about the new cards about as much as you are. Just bask in the newness and the shiny. Open some Mythics. Show off.
Enjoy your weekend, losers. I'm going to draft all day on Saturday. I'll probably be writing my ManaNation article on it. Read it please.