I am clueless about how the colleges notify us about the acceptances and the rejections. Do they do it by email or do they mail us? Moreover, when does one actually hear from the universities? I have a friend studying at Yale and she told me that we'll only start hearing from them in February or March.. Is that true?

Hello,
Most schools send responses via email in Feb. or March. If you applied under early decision at a school that offers this option (such as Columbia) then those decisions went out Nov. - Dec. hope this helps. Good luck with Yale. I went there for my Ph.D. and loved New Haven once it grew on me.