I'm still learning too, my B3000 is my first fuel injected vehicle.
It's not so bad really once you get to read the symptoms in relation to the codes what the computer throws out.
Ron said, very rarely are the sensors the problem, it's usually a bad connection on the plug to the sensor and/or a bad ground.
You need to get yourself an ohm meter, they're cheap and indispensable.
With that you can do simple continuity tests and check the resistance of your plugs and wires.
A simple visual check on your plugs goes a long though, they should be very clean looking.
That's a good sign that the idle fell when the IAC valve was disconnected, probably around 400 to 500 rpm. Defiantly that disconnected hose caused a major vacuum leak.
Here's an article on how to test the MAF sensor and it's various functions.
Read through the article a few times and get comfortable with it. Don't try and absorb it all at once.
My only caution is to be carful when testing any sensor, don't short anything out or accidently touch a live wire somewhere.
The key is to take your time and be by yourself and in quiet environment.
About your spark plug wires, once you have an ohm meter, the longest should have no more the 30,000 ohms or 30K ohms.
You can test for spark and it may have good spark, but under load and/or real world conditions, they won't work.
How old are your wires ?
Some wires have Kevlar in them, that stuff breaks down and the wires easily become "stretched" from handling.
The breaking down of the Kevlar causes the resistance to clime.
The reason why I mentioned your fuel pump is it would be causing a lean situation if it's not putting out enough pressure.
This is a grey area for me, but it would make sense and may cause the computer to throw up those codes.