Emergency!!! haha need some help

So after 4 years i came inside to find my macbook (2007) not loading anything!! it was making a tic tic tic toc sound repeatedly so i manually shut it down, i tried to restart the sound started and the load screen, the white one with the mac symbol disapeared and a file symbol appeared with a question mark, i am assuming that my hard drive is toasted, not surprising i am extremely hard on it using it at like 99% capacity while i edit large quantity of 1080p video.

so i google the removal process, and i must say mac is an extremely smart company =D it is so user friendly!!!

so i have a Seagate momentus 5400.3 160 gb hard drive that came stock in my computer, and i am thinking about upgrading to a 250 gb, or 500 depending on the price, i don't wanna sink a pile of dough becuase in a few weeks a plan on buying a brand new macbook pro

now my question is how does the time machine backup work? i have 140 gb ish on a 2 tb external hard drive, i am getting a new hard drive going to a friends house to get snow leopard re installed (got it off him for free) then what do i do? i want my itunes library and my iphot library back how do i do this?


i am very very proud to say that after 4 years of about 16 hours a day my hard drive broke =D haha sounds to me like this make is a much better investment then i ever thought possible =D