As an adjunct to my regular job (teaching) I have taken on the task of developing an appointment booking system to be deployed on the school's server (SQL Server 2008 R2 / IIS 7.5).
I have been writing and programming web pages since the very beginning, so I have a good knowledge of the client-side (including jQuery). I also have some knowledge and experience in database programming (Access and mySQL). For the last several months I have been been teaching myself server-side programming (mainly via the Apress books on MVC3, ASP.Net and C#, as well as through the tutorials on Pluralsight.) I shall be developing the system in Visual Studio 2010, and have written one or two basic practice solutions in MVC3 that work fine on my local development system.
My question: What is the single most important thing I should know or do as I embark on this project? (PS. I am committed to using MVC3, Entity Framework 4.1, C# and Visual Studio.)