First and foremost i'd suggest CaptnDucks DF2012 tutorial youtube playlist, as my personal favorite tutorial for new players. I'd also highly recommend having the wiki open and searching for any concept, command or workshop as you use or build them, to get a better understanding of how they work.
This is a personal preference of mine that not many people share, but i'd suggest that a new player jump straight in to vanilla DF, with only DwarfTherapist running alongside. I feel that texture packs look mismatched and ugly, and that over-relying on a texture pack can make it more difficult to cross over to playing other great ASCII games. Elements like DFhack and the lazy newb launcher config also provide far more depth and options than a new player could even consider.
Apart from that, a couple of important points to consider:
+ Never embark on any map tile with an aquifer unless you're certain you know how to get past it.
+ Always have more beds than you need, otherwise your wave of 30 migrants will be sleeping on the floor.
+ Put down plenty of stonefall and cage traps in and around the entrance of your fort, rely on traps to stop sieges for now.
+ People may tell you not to bring cats because of !!CATSPLOSION!!, but they're very useful for catching small vermin that would otherwise annoy your dwarves and feed off your food stockpiles.
+ Make sure to have a trade depot built and plenty of rock crafts to trade, if your fort isn't self-sustaining you can buy food, seeds and booze from the merchants.
+ Use DwarfTherapist to assign useless peasant migrants to menial tasks like mining, stone smoothing or fishing, otherwise they're just a drain on your resources.
+ When your fort is populated enough that the more useless peons can handle hauling rocks and items, use DwarfTherapist to disable all hauling tasks for important dwarves like miners, masons and craftsdwarves. This will allow them to spend more time on their jobs instead of carrying boulders.
+ Once you get a manager dwarf, you can give orders to produce certain quantities of items (eg: produce 20 beds) and the manager will automatically assign tasks to the appropriate workshops until the order is fufilled. This is Easier than micromanaging in most cases.
