1) Yes, you should crate a database to sotr information about the properties that are to be listed.
1a) I would recommend using MySQL.
1b) The complexity of the database depends on the information that you want to display on the website. If the website will only display the bare bones information about a property, there is no need to crate a database that stores all of the property details however, if you plan to display the property details on the website, that infomation will need top be stored in the database.
1c) You can use DataAssist to create administrative pages to insert Update or delete records.
2) Yes, using Site Assist, DataAssist and security assist, you will be able to create public and administrative sections of the site and allow administrators to manage the database.
3) PHP, ColdFusion and ASP Are all Programing languages used to develop dynamic websites.
3a) You do not need to have any of these installed, but it doers help to speed along development.
3b) Go with PHP / MySQL. Moving forward, we will not be supporting the other languages.
3c) Yes, they are used by the server. Before getting started, you should familiarize yourself with Dynamic Site Design. I would recommend the Foundation PHP Series by David Powers:
As well as our Web Development: Before you begin tutorial: