Is there any good reads for Goodwillie calculus out there? I have a basic understanding of combinatorial species and category theory and now I am curious about this functor calculus or Goodwillie calculus. Can anyone kindly recommend me a nice place to start. Do I need to delve into its algebraic topological origins or is there a "ready made" exposition available? 
 A: Goodwillie's original papers are still perhaps the best reference.  Specifically, Calculus III is very readable and develops more than enough material to keep a beginner in the subject busy for quite a while.  The first few sections of Calculus II would be helpful if you aren't familiar with cubical diagrams, though for this particular area, there is also a wonderful draft by Munson and Volic titled Cubical Homotopy Theory.  Calculus I isn't really needed for the second two papers, and if you're comfortable with cubical diagrams, then Calculus III can be read without reading either of the first two papers.
If you are into other flavours of Goodwillie calculus, I'd like to suggest taking a look at the 'discrete' calculus developed by Johnson and McCarthy for functors from a pointed category to an abelian category.  The goal of constructing polynomial approximations is the same, but the new setting gives this type of calculus a far more algebraic flavor.  If this is something that interests you, their paper Deriving Calculus with Cotriples is also a good read.
There are of course also orthogonal calculus and embedding calculus, but I'm not familiar enough with these areas to give any good references.
