Whats the premise of SR4?
The premise of SR4 is cyberpunk meets D and D.
Basically in the early 21st century magic came back. Dwarves and elves were being born all over the place, amateur mystics were finding out their shit really worked. Dragons showed up.
Later, some folk begans spontaneously turning into orcs and trolls.
At the same time society as we know it was falling towards dystopia. Large megacorporations were able to declare their territories no longer subject to governmental law. The United States fractured into disparate areas as the Native Americans used some Whoa Fuck Mojo to take back the West and divide it amongst themselves. California seceded from the U.S., then tried to come back, but the remaining U.S. was "No, you wanted out, sack up." So the Japanese invaded Cal Free State. The southern states finally managed to secede and created the Confederated American States. In desperation the remaining U.S. (the midwest and northern east coast states) joined with parts of Canada and formed the United Canadian American States.
Elves took over Oregon (Tir Tairngire) and Ireland (Tir Nan Og). They're spooky and have their own agenda.
Technology exploded all over the place and people began jacking into the Matrix, linking directly with the Internet via a neural connection. Just like in Neuromancer and other William Gibson works. They also managed to link directly to cars and other vehicles and even weapons.
Later, that all changed with edition four, the one we're working with now, and it all went wireless.
You have some basic archetypes to work with:
Street Samurai: Cybered up badass motherfucker.
Mage: Pretty self-explanatory.
Shaman: Like mage but all hippie.
Hacker: A person who interfaces with machines directly, either computers and hacking the Matrix or machines and vehicles or both.
Adepts: Magic users who channel their magic in ways different from the standard mage or shaman. Most common are Physical Adepts who use magic to become bad ass motherfuckers.
You can choose to be a human, orc, troll, dwarf or elf. They each have their own peculiar benefits and drawbacks.