Calculate First Day Of Current Year

Question

Hi all,

First of all I must say that I am a newbie when it comes to net (C#).
Here is my problem.

I need:
1) Calculate First Day Of Current Year (01/01/2012)
2) Calculate First Day Of Previous Year (01/01/2011)
3) Calculate Now Of Current Year (26/06/2012)
4) Calculate Now Of Previous Year (26/06/2011)

Can you explain any one or any sample code related this...

Your help would be very appreciated.
thanks for your time and hints.

Thanks in advance,
Chevy.