A site plan review is basically a zoning permit that is issued by the Planning or Zoning Commission. You will submit an application along with any applicable plans and the Town staff will review the documents and make recommendations to the Commission. You or your experts will make a presentation to the Commission explaining the project, answering any questions, then the Commission will either vote, or continue the application if they need more time or more information is needed. There can be a public hearing, but they are not required and most Towns will not hold one unless the application is particularily unpopular for some reason.
These differ from Special Exceptions/Pernits in that if your application meets the zoning requirements, it HAS to be approved and within a specific period of time. There is very little discretion left to the Commission. Generally these kinds of permits are easier to obtain in most Towns. A complete application is the key to your success and we can certainly help you with that review.