Q: What happens after we die ? 

Ans: life after death is very interesting question and always generate lots  of curiosity  and reflects as a  basic symptoms for the person embarking on the path the self realization , the answer of this question is elaborated in Garud  puran as well as shrimad bhagvatam and Brahmasamhita, i will  try to summarized it as short as possible ,

we , A human body is divided in to two sub bodies

1) Material Body 2) subtle body

1) Material Body is comprised of 5 Elements

 Air , water , Either, fire ,Earth

2) Subtle Body is comprised of  three elements

      Mind , Intelligence and False-ego

     so if we do the dissection of self , we looks like this  

Now when we die ,we lose our Material Body and initiate our traveling with the subtle-body !

so Mr.Human is separated in  two bodies , a)  Mr. Material b) Mr. Subtle  

after the death ! Mr Human  is left on the planet , and will get  burned or buried and his or her picture is   hang  on the wall with Rs 20 Garland :) , while   Mr.Subtle is ready to go to Airport  to catch a flights based on his  Karma and Kama( Deeds and Desire) ! these both plays an  important roles for our next body  , so its very much important to purify our desire ( KAMA) and execute our karma , the Ideal process is recommended by Krishna in Geeta is called Bhakti Yoga or Devotional Services ,

Now as per Geeta  Text 14.18 , our destination is categorised based on three  mode (sato,Rajo,Tamo)

"Those situated in the mode of goodness gradually go upward to the higher planets; those in the mode of passion live on the earthly planets; and those in the abominable mode of ignorance go down to the hellish worlds."

as krishna mentioned above ,  there are  14 regions of material world  ,  divided as  :  6 Upward , 7 Downward , 1 Bhulok ( Earth)

6 Upward: Bhuvrlok,  SwargLok , Maharlok , Janlok, Tapalok, Satyalok or Brahmalok

7 Downward: Atal Lok , Vital Lok, Sutal Lok ,Talatal, Mahatal, Rasatal, Patal

depends on the Lok you belong ,you  will get a  body , sometimes you destined to get the  same Lok where you die but with the Lower Body , then in that case you will be  sent in the training camp to get use to that kind of body  , for example you destined to be pig !! so you have to get train to eat stools , and that training place is called Narak where Yam Dut will give you a hands on training :) , Details on this part is explain in "Garud Puran"

As krishna said in Geeta 8;16

"From the highest planet in the material world down to the lowest, all are places of misery wherein repeated birth and death take place. But one who attains to My abode, O son of Kunti never takes birth again"

The entire Material Universe , doesn't matter how comfortable or opulent  or attractive it appears  , they are not even close to what is in Spirituals world ,as Material world is  not excused from Birth and death ..   these planets are perishable so their citizens too.. ( Including the Topmost Living being in Material world , Bharm Dev )

Above is the rough sketch of the person who destined to travel in material universe and force to take repetitions of birth and death based on Kama and Karma , there are other elite platinum passengers at the airport who enjoy the VIP lounge facility and has a Special Flights :), Those are no one but the devotee of the Lord and  waiting to catch a flight for Krishna Lok  , because Krishna said in Geeta 15.6

  "That supreme abode of Mine is not illumined by the sun or moon, nor by fire or electricity.        Those who reach it never return to this material world."