Depending on where you're from you'll face different challenges. If you're an EU/Schengen citizen you can pretty much just mosy on over here. If you have a full-time job and/or enough money, as well as some form of health insurance you'll be able to get a personnummer quite easily. If you're outside of the EU things get trickier, but having a job lined up here will make things easier.
There's also the spousal path, though given our current nazi-xenophobic government I'm expecting a lot of those avenues to get tougher.