The transistor bias current is equal to V(R4) / R4. So, for example, if you want 1mA emitter current with a 10V supply, then you want the emitter biased at 2.5V, This gives R4 = 2.5V/1mA = 2.5kΩ. The collector resistor is then selected to be the same value.
Since the emitter current is determined by the emitter voltage across R4, you want to set Vb to equal V(R4) + 0.7V = 3.2V in this example. To minimize the effect of the base current in setting Vb, you make the current through the series value of R1 and R2 to be at least 1/10 of the emitter current. The ratio of R1 and R2 is selected to give the desired Vb, of course. That math for that is left to the reader.