Well, I'd like to be more helpful but I'm not really sure exactly what it is that you want to know. A 19" flat screen monitor is (rather obviously) designed to be used with a computer so, by definition, it's 'suitable for computer use'.
A 19" monitor is probably a 'non-wide' monitor, such as this one:
http://tinyurl.com/2cr9hc3
My own preference is to use a 'non-wide' monitor but they seem to be regarded as a bit of an oddity these days in places like PC World. I'm using a 17" monitor, which is big enough for my needs (and ideal for the limited space on my desk) but some people seem to want massive screens (although I've no idea why!).
To find out if the monitor you've seen is any good you need to find the make and model number, then google those details to find out the contrast ratio of the monitor. My PC (£15 in an auction!) came with a very old flat screen monitor that only had a 200:1 contrast ratio. It would have been fine for word processing but no good for anything else. My current monitor has a 10000:1 contrast ratio, which is the type of figure (or better) that you should be looking for.
Chris