Sorry, there's no one place where you can get all this information. There are a couple of artists' handbooks that cover pigments in a fairly comprehensive manner if you're really serious about getting a good grounding in them, your local library might have a few of them. There are also some websites but I should warn you that the specifics of a colour can be highly dependant on the exact paint in question in a number of ways, so even knowing generic pigment info can only take you so far - paints made with the same pigments from Michael Harding or Old Holland won't be remotely the same in use to Grumbacher Pre-Tested or Gamblin because they're not made to the same philosophy.
Since you mention Van Dyke Brown that's a good example of variability because almost every one is now a hue and not the real thing (the real pigment is fugitive so you wouldn't want it anyway) and as a result it is made from various combinations of earths, real and synthetic, and a number of blacks so you can imagine how much it might vary from range to range. That is really just the tip of the iceberg.
The basics on opacity are fairly easy to come by, most makers use a four-point scale to class their paints and this information is usually on the colour charts in leaflets and on their websites so check your own brand(s) accordingly - Talens, W&N and Daler-Rowney have this that I recall and Gamblin's website has a little blurb on each colour giving an overview of its properties.
Other than that you'll have to pick up the information from personal recommendations and hands-on experience.
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On paint selection in general I wouldn't get too hung up on this sort of detail. Although it's important to know the masstone, undercolour and tint of your paints to be able to use them to the best of your ability, if you buy a tube of oil paint and it's not exactly as John Smith's recommended tube of the same colour you can't exactly go and buy a replacement because before you know it you'll have 50 tubes of oil paint that you'll barely be familiar with, in addition to having a lot less money to spend on models.
My advice: buy the basics (12-15 colours is about right), learn them well and you'll probably never feel the lack of anything more exotic.
Here's what I would suggest:
Phthalo Blue Green Shade, PB15:3 (or Prussian Blue, PB27)
Ultramarine, PB29 (French Ultramarine is usually very similar or the same)
Cadmium Red Light, PR108
Quinacridone Rose, PV19 (or Permanent Alizarin Crimson)
Cadmium Lemon, PY35
Cadmium Yellow Medium, PY35 or PY37
Mars Black
Titanium White
This concentrates on opaque paints as much as possible because coverage is so important to us. Don't skimp on brand on the white, an expensive one will serve you well (better pigmentation = better opacity) and can help to balance out some of the very strong pigments like Phthalo Blue and Quinacridone Rose.
Most of us rely on a few earths as well, my favourites are:
Yellow Ochre, PY43 (or Mars Yellow, Gold Ochre or similar, PY42)
Red Oxide, PR101 (or English Red, Light Red or Venetian Red)
Burnt Umber, PBr7 (I like Raw Umber but it's not absolutely vital, since it's cheap you can add this if you want)
You'll notice there are no greens since you can mix these so easily and also no violets since we will practically never need a brilliant violet in the hobby and you can mix any type you like from the above colours. If you do want to add any of these Chromium Oxide Green, PG17, is a good choice being the most opaque green available, a bit dull but a good base. If you want a basic dark green Phthalo Green Blue Shade, PG7, is probably the most versatile; Viridian, PG18, is an option but it's much weaker and a bit dull (often a bit more expensive too). Dioxazine Purple is a good blue-violet paint, if you would prefer a red-violet Quinacridone Violet, PV19, is a good choice.
Einion
Maybe that is the reason I want to know the difference between them 
