To answer your questions directly;
-What needs to be done before you visit the shop?
Is the shop going to be doing the tune, installing the intake, or both? You can install the intake in 15 minutes and get a custom mail order tune or a "can tune" (i.e. superchips) without dealing with a shop, unless the shop has a dyno and is doing the tune. If you are still set on going to a shop, call them to get the details.
-What is all involved in a tune?
Getting the handheld tuner, plugging the handheld module in the diagnostics port, hitting a few buttons, waiting two minutes, and unplugging the module. It is very easy to do.
-What cost to expect for a tune?: superchips ~ $300 ; PAT G = $625. Both of these options are one upfront cost for infinite tunes.
-Is a tune needed?
If you are only planning on getting an OTR intake installed, no, a tune is not required. However, you will get more power than adding the intake alone, and it will greatly improve the driving characteristics of the car. I highly recommend getting a tune.
Here is my opinion, if you are only planning on doing an intake, an expensive custom tune is not worth it. You will be fine with a cheaper "can tune" like superchips, you can download the tune file for the intake on your computer with their software. A can tune such as superchips will get you 80-90% of the performance of a good custom tune at around 50% of the price on a car that just has an intake. Just my opinion.
Like pony killer said though, if you are planning on doing more mods down the road, get a good custom tune off the bat and make sure they do re-tunes. So you don't have to buy another tuner later on. Superchips cannot support very many modifications. I have Pat G's mail order tune and have been very happy with it. You will never find a bad or even a neutral review of Rick C's work either, nothing but praises.
Hope this helps
2009 GT sport, prem., roof PBM - Red/Onyx
Rotofab, LS7 MAF, Pat G tune, Kooks mids, Mangaflow, 3.45 gears
Last edited by Pontiac88; 10-23-2014 at 08:31 AM.