DarkBASIC ( Classic and Professional ) comes with a Book. I'm not too sure if DBClassic comes with a tutorial book, but DBPro does. ( With two tutorials in it ).
Support is universal for all Video Cards and Processors. This is because it runs entirely through DirectX ( 8.1, 9.0b for Pro ) and Windows.
There HAVE been reported problems with Vid cards ( not so much with DBC, but with DBP ), which have almost all been fixed by a simple Driver update.
I own Both DarkBASIC and DarkBASIC Professional, and I must say that it is much more worth your while to buy DBPro.
It has support for DX9.0b, and in the coming months ( and over the next year or so ), there will be many, many new features added.
DBPro's 2D speed is much, much more pleasing than that of DBC, and I am pretty certain that in the 3D section, DBP can handle much more polygons on screen at a time.
Also, since DBClassic has been finished, there will *never* be anymore updates to expand upon the language.
Whereas DBPro is continually being updated, and I expect will be for at least another 3 or 4 years ( and probably then for longer ).
The good thing about DBPro is that it offers all the standard commands, which make it simple for the novice 3D game programmer, but it also has, on top of those, more complex commands along with upcoming support for more advanced features. This means that as you become more indepth with the language ( as I have ), and you don't find it so daunting any more, you can move along to the more advanced commands, and see how much more powerfull they are, and how much easier it becomes to do "advanced" effects or caculations for your game.
Anyway, enough of the advertising.
Hope this info helps
Jess.
PS I have also emailed this to you.
PSS.
DBC = DBClassic = DarkBASIC "Classic"
DBP = DBPro = DarkBASIC Professional
[EDIT]
Oh, and ignore eBusiness, he's a Blitz BASIC coder ( as his sig says, "Blitz Basic coder, please flame me." ) So I wouldn't trust his word

- JK of course

[/EDIT]

Team EOD :: Programmer/Logical Engineer/All-Round Nice Guy