People who work at car shops:
 

I just want to get a better understanding on how a shop is run. My main question being, say you have 7 cars in the shop all needing something to be done on it... Do you gradually work on them all or do you finish one move on to the next etc. etc... ?

Depends. You would generally try and diagnose them all if they need to be diagnosed, then you need to get customer approval to start work, then you need to get parts. Not all cars need all those steps but basically you work on the cars as parts and approval are given. When I worked as a repair mechanic there was alot of waiting involved before you get the go-ahead to start working on them.

What about a performance shop, where most cars are getting parts put on etc. etc.

most shops ive hung out in are a time/effort basis... you get a ride in that needs 3-4 days worth of work done, you get started on it, if a car pulls in for a sub hour install, you knock it out, get paid and go back to the big project.

time is money, so you tell the customer with the larger project that its going to take longer then you know it will so as to allow for the little jobs that will gain you quick money...

edit: then again it also depends on how big your shop is, how many people are working for you, and what actually is going on. most shops ive been at have been 5-10 car bays and 20+ people working there. shit is always going on!

right, my friend and his dad run a shop in jax, and they do basically everything from body work to engine rebuilds. They'll have people drop cars off for a week or 2 and just want it fixed, and they'll work on it when they have nothing else to do, and sometiems someone will come in and need a valve seal replaced immediately and wait on the car so theyll do it quick.

from my experience its basically easy to structure:

Waiting customers> same day drop offs > big repairs/installs that take time > personal cars.

having worked at performance/dyno shop during college, it really is a give and take situation. As said if it takes diagnosing, knock that out first and wait for approval to move on repairing. Big jobs (builds/race prep/caging) are your main task (on going) and small side jobs will roll in and get knocked out quickly just to keep things rolling and to keep from losing a customer.
Jobs that require lots of work, fabrication, custom work, etc...generally is a 1 week+ project and the customer is told that ahead of time. That is assuming the parts are on hand before the car arrives.
I always preffered customers to hold cars until parts arrived and then drop off for work. Keeps more open space and no down time on lifts.