Do any of these radar spotting programs function in real time, as in without any time delays?
Depends on how hard you define real-time. A 100% real-time is impossible. The Airframes (planes) you were receiving via your Radarbox are delayed a few hundred ms up to a couple of seconds. This delay depends on your machine speed and the time between the position gathering and the transmission of the ADS-B Signal of each received airframe. Traffic which you receive via the Real-Time network is delayed a few seconds, due to all the precessing and transmission-stages a position data must run through.
HEX: Each Airframe has a definite Mode-S Address of six hexadecimal numbers to be securely identifiable. EG: 400DB3 is the HEX address of G-EZAP of easy jet Airlines. Further the HEX is used by RB Software to look up in the Database more information of the received airframe like registration, Type, ICAO designator construction number, operator and on several airframes two links to a downloadable picture.
SQUAWK: please ask the wikipedia:
http://en.wikipedia.org/wiki/Squawk_code and take look here:
http://en.wikipedia.org/wiki/ADS-BTrack: In the meaning of tracking, which means to follow a particular Airframe, monitor its movement over a longer time. Or to track down information about a formally unknown Airframe until all necessary info for the database is gathered?
For someone like myself, who is new to all of this and also not really looking to subscribe to anything at least for now, how is something like this best used?
That depends on what you want to do. For me it's a way to burn a lot of time (and sometimes money). You can use it as a spotting appliance to be ready to "shot" the airframe of interest. Or you can use it 24/7 like me two seek out rare and (for me) interesting one airframes. Additionally I'm trying to support the database-updaters team on this forum to fill the database by giving them the unknowns of a day. Finally RB respectively flight tracking is a great hobby, in which can spend many hours of time and a lot of money. But someone has once said: The definition of a hobby is to get the least benefit by using the maximum possible effort.