Astronomy help stellar evolution?

I am doing a project for astronomy and I am having trouble finding some of these answers. I am trying to look up the information on my own it's just not going so well, any help would be very much appreciated.

Stage: Nebula

a) How long does this stage last?

b) What elements are present?

c) Why would the nebula begin to contract/shrink?

d) As the matter collapses, what does the nebula look like and what does it do?

Stage: Protostar

a) How long does this stage last?

b) Describe the protostar

c) Why does the protostar heat up? (two reasons)

d) How hot must a protostar get in order to become a star?

Stage: Main Sequence Star

a) How long does this stage last?

b) How is the energy generated?

c) Why is this stage stable?

d) Which elements are being used up? What type of fusion?

e) Why does this stage end and what happens?

Stage: Giant/Supergiant Star

a) How long does this stage last?

b) Why do main sequence stars become giants or supergiants?

c) What type of fusion (which elements)?

d) Where does the energy for fusion come from?

e) Why is this star expanding?

f) Why does this stage end and what happens?

Stage: Planetary Nebula

a) How long does this stage last?

b) What is a planetary nebula?

c) Why is there no fusion?

Stage: White Dwarf

a) How long does this stage last?

b) Why is there no fusion? What elements exist?

c) What happens to the giant star as it becomes a white dwarf?

d) Is it still glowing? Why?

e) How is a black dwarf different and why are there probably no black

dwarfs in the universe.

Stage: Nova

a) How long does this stage last?

b) What is a nova?

c) Explain how nova’s occur.

d) What type of fusion is occurring in a nova (which elements)?

e) What happens when this stage is over?

Stage: Supernova

a) How long does this stage last?

b) Review what happens to a supergiant that would make it’s life come to an

end.

c) What produces the energy necessary for fusion of heavier elements to occur

d) Which elements are fusing?

e) Why does this age end? What happens?

Stage: Neutron Star

a) How long does this stage last?

b) Explain what it is and what it is made of.

c) Give an example of how dense it is.

d) Why is there no fusion?

Stage: Black Hole

a) How long does this stage last?

b) explain what a black hole is.

c) What is the difference between a black hole & a neutron star?

d) Why do some supernovas become black holes vs. neutron stars?

e) What do they give off?

f) Where do black holes usually exist?