Oscillation Motion Frequency: Spring & Block

[SCI2007]

A spring is hung from the ceiling. When a block is attached to its end, it stretches 2.0 cm before reaching its new equilibrium length. The block is then pulled down slightly and released.
What is the frequency of oscillation?

I'm totally Stuck help would be appreciated...

 

[Astronuc]

Knowing that the weight of the block is mg, where m is the mass and g = 9.81 m/s² must = the spring force = k * 0.02 m,

thus m 9.81 m/s² = k 0.02 m

Then what is the relationship between angular frequency and k and m?

http://hyperphysics.phy-astr.gsu.edu/hbase/shm2.html#c2