if you search the web for tuturials on specific genre sounds, they'll be presented using some instrument, chances are in 80% of the cases you'll be able to translate that know how into your Virus - since most subtractive synthesizers share a similar structure, it doesn't matter much which one you're using. Virus is a very capable machine and sounds very good, suited to all the genres I can think of, factory presets are just based on the public they think they have, it's a marketing decision more then anything, really.
it's best to ask about specific sounds, with examples, so as to get some good guide lines about the basics of such sounds. plus, programming a synthesizer isn't a daunting task, nor is it something that requires you to learn thousands of strange, difficult to grasp concepts, it's a matter of looking at the different things one at a time, like oscillators, envelopes, filters, lfos, so forth and so on, and experimenting with this things, starting with a blank patch. one important thing is: at first don't obsess about getting a specific sound, that comes with time, once you're used to connect some settings to qualities of sound.
so yeah, do as Berni says: search around for patches that get near what you're looking for and analyze those, really look into them, see what's going on, and then try to build some from scratch based on that know how. the Howard Scarr manual, on their website, provides a good journey into such matters: how you can approach and analyze patches, things to experiment to get to know the machine a little better, some careful laid out explanation of the main features and techniques to, and is quite an enjoyable read to, not nearly as boring as a manual. a combination of this things will get you up to speed in no time, and you'll find yourself feeling much more empowered and inspired and loving your new machine much more to. the more you put into it...
