Dirtwarrior,
Bill Hitchcock is one of the guys who helped develop the Prominator, and the last time I talked to him (before Christmas), he was still one of the main guys there. As far as the plug and play aspect, it depends on the computer in you vehicle. MOST mid to late 80's Blazers have a 1227747 ECM running things. Inside the ECM lays the chip. The chips in the 7747 ECM DO "snap" into place. This is replaced with the flash based Prominator complete with a home type computer interface (plug in connector). From what I understand, and I may be wrong here, the origional chip holder is de-soldered and it's flash based replacement is soldered into place. Now with the the newer MEMCAL equipped ECMs, the Prominator will just plug right in.
The .bin is the program that is stored within the chip. This is what you edit to tune the vehicle. This is where the software comes in. I primlarly use TunerPro, but you can also use TunerCat with the same results. Some guys I know actually disect the .bin line by line, make thier changes then reassemble the whole mess and burn it in to thier chips. Now I'm not THAT dedicated to extracting every drop performance out of my BLazer, but it is possible. One other thing, you also need a software package to see what the ECM is seeing so that you know what changes need to be made. Almost everybody uses Win ALDL to do this; from what I've heard, the latest version of TunerPro will also let you do this too.
One of the best things about the Prominator is that, with the pro version, you can have somebody drive the vehicle while you monitor the engine readings and actually make changes to the .bin and load the modified .bin into the Prominator while the engine is running.
A good starting place is
www.thirdgen.org . There are some real gurus over there who have forgotten more that I'll ever know about chip tuning. They hang out on the DIY Prom board and are very helpful, and don't mind helping us truck guys out either.

Don't forget to use the earch engine over there either, it will give you enough information to provide hours of reading.