Listening to Mic Audio through Headset or Music System

Hi GAry… I am a complete Mac fan and switched from Windows. I wont ever go back to it. Though there is one thing I have not been able to crack !
I am a passionate singer and I often use to sing on my windows machine using a microphone headset and actually hear myself while i sing through the headset along with the Song playing. Also I could connect it to my music system and I hear the song and me singing.
I also sing through Voice chat software like Skype where the other friend can hear my voice as well as the Music too !
Now how is all this possible on a Mac? I tried Sound flower etc but find them complicated to use ! On the iMac I can record myself but the Audio is not audible through my headsets. only the music is heard ! Windows had a WHAT U HEAR function. I want to be able to do all that with my Mc. I have a Bose system that I want to stream the output of the itunes song and me singing it, live !
Please Advice !
Thanks a million !
—–
Cyrus Dubash