Hi
I have a cake to make for 26th May and they have asked if I could make it with the exploding fondant stars etc. Can anyone please explain or tell me where I can find a tutorial on how to make this look on my cake. I would really appreciate your help asap, so I can get it right in my head.

http://www.wonderhowto.com/how-to-make-fondant-icing-shooting-stars-for-cake-decorating-345840/
This video shows you how to make the stars.
I would put them in a flower pick or wide straw with fondant pushed inside to hold the wires up so you can fiddle with the positions.
If you want the cake to look like it has been ripped by an explosion you need to ice the cake and cover the top with a circle or square of fondant depending on shape of the cake.. I woulld then put some powdered sugar over this and then cover all the cake with fondant making sure that the top layer does not stick to the fondant underneath. I would then use a circle of paper folded in to about 8 triangles and open to use as a guide to mark out where you will cut slits on the cake. Then carefully peel back the eight triangles . use some saran or kitchen paper to hold up underneath till dry.you can fill the centre with dragees or similar if tou like.
Hope this all makes sense.

Exploding?!? Sounds like a job for Duff Goldman!