For 1.6, you can farm wheat, reeds, cacti, and if you want to get a little complicated, pigs, cows and sheep. I'm not sure about mushrooms at this point. I think they became farmable in 1.7.3 or 1.8.
Wheat, Cacti, Sugarcane/Reeds, and Mushrooms (yes, they are farm-able, look up on the Wiki or YouTube to find out how). Soon you'll be able to farm melons and pumpkins.
This thread bores me.