Once I have wrapped on a shoot and I head home to begin the post processing/retouching - whats a reasonable amount of time to have the client wait before they get their final images?
As I grow I aim to do a lot of post work after the shoot, to make what I hope to be my signature style.
When shooting landscape/wildlife, a quick crop, spot removal and curve adjustment was all that was usually required, so I could get my images out pretty quickly. This wont be the case if I start to get more fashion clients.
Is there a "we need those images now now now NOW!" attitude or is there an acceptance that some stuff just takes a while, and there arent any 'make it awesome and cool' buttons or filters in photoshop
As Dshelly said it depend on your client and how you organise your work. Depending of the work it can be less than 24 hours to "some" days, depending of what you need to do but primary on your skills and/or team.
As I grow I aim to do a lot of post work after the shoot, to make what I hope to be my signature style
This is IMHO a very bad goal to aim or hope. The world is big and we are legion. Your "signature" will come with your name and fame, not your "pp" skills. Just focus on the work and be pro, that is what clients expect and if the work is done correctly you'll be rewarded (more clients, publications...).
So do not mix personal and professional. You personally want to make your "own style" but professionally you'll do what the artistic director/client want and, with time, you might insert some of your "own style" if possible.
Sometimes you'll provide a raw and then the client's retouchers army will make the job, sometimes they will ask you impossible things... never over-sale yourself. Also you might start to build your own team. A good MUA can save you hours of PP for example.
Hope this help, take care.
