Really so many things to read oh..  but here's my very basic overview u need to know.

The LCD panel itself is manufactured by only a few companies. Not all brands that sell LCD monitors actually manufacture the lcd itself. Hence inside a Dell, you can find an lg or Samsung lcd.  So in Samsung's case, the A,S,C are indication of different panels inside the same Samsung plastic.

LCDs can be categorized by it's technologies, each with it's own good and bad.  TN, PVA, IPS are just shortform names of the different technologies used. Knowing the characteristics of each can help you identify what you are getting. After that, find the one that suits your needs. Specifications are sometimes not accurate. Numbers like contrast ratio, response times can be different from the actual values. The usual marketing ploy to make it seem better.

Price also varies with the type of panel.  Most 22" are TN types and 24" are PVA, 20" are sometimes IPS/MVA. It seems that there is less wastage in manufacturing the 22" sizes and that lowers costs.  This is why some 20" are more expensive than 22" and a jump from 22" to 24" is maybe Rm1000 more.

The whole screen is composed of dots and the resolution is actually how many dots across X how many dots going down like 800X600. Each LCD size eg. 22", 19" has 1 native resolution that will look the best . Other resolutions will run, but not as sharp as the native resolution. The measurement of the 17", 24" thing is actually from the bottom left corner to the top right corner of the screen, like a slope.

Aspect ratio like 4:3, 16:9 (widescreen), 16:10 (widescreen)  is horizontal resolution  divided by the vertical resolution . 
Eg. 800/600 =1.333333  which is the same as 4/3.

Each brand has it's return policy on Dead pixels. Dead pixels are like dots on the screen that is not functioning, doesn't change color like the rest. So if your screen has less dead pixels than stated in the policy, you may have a hard time to get a replacement.

DVI, D-SUB, S vid,  HDMI refer to the connectors and wires that connect your monitor to the source (pc, notebook, dvd player). The more you have, the better. HDCP, is not a connector. It is some protection standard of the video signal from the source to the monitor so that people cannot copy the signal easily.

Don't panic when the picture doesn't come out as you expected when you just bought the unit. You must adjust it using the plastic buttons on the lcd itself and also in your pc's display software (driver) to get a satisfactory result. Sometimes, trying different media players will give different results as well.

Many of the lcd stands at the back, can be removed so that you can wall mount or replace with another stand.

oo... lunch time, but this info should help you get started. Good luck 2 you with your lcd purchases.

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a few things to help or confuse you !! :

Dead pixel buddy, fills ur screen with a color, so that you can detect anything dead.

hardforum , long discussions on particular lcd's

huge wallpapers for your screen