Look up "blue card scheme". If you have a university degree, and you interview somewhere and get the job, and your salary will be over 1.5x average national gross salary (In Germany this calculates to around 39KEUR/year), you will get a residence permit, none of this "is there an EU citizen qualified for the same job" check.
As for the salary, I can only say a German computer science graduate being offered a real programming job would probably laugh at anything below 45K, and is looking at around 50K. After tax this comes to around 30K/year (don't quote me on this number), which will be enough to live if you're single, for more costs of living you can check numbeo.com
Ah.. you can see my response above about that. They have residency permits for the purposes of study, you have to show that you can finance yourself or have a sponsor (e.g. a parent).
As for the salary, I can only say a German computer science graduate being offered a real programming job would probably laugh at anything below 45K, and is looking at around 50K. After tax this comes to around 30K/year (don't quote me on this number), which will be enough to live if you're single, for more costs of living you can check numbeo.com