Process to take during initial stages of a new database project

I will be working with an architect to decide on creating a new oracle database that will have a small amount of users but a lot of data (around 500gig).  This is my first time doing this from scratch (not first time installing, but where I am involved from the ground up).  Normally, these type of decisions have already been done by the time I am to perform the build of the database,  

Can anyone point me to or provide a document of the various questions that should be gathered to determine what type of database would be best suited (i.e. RAC, stand-by, stand alone, etc.),  review on redundancy.  As well as what other questions to ask the application team to effectively create/configure this database?