im going to break this down into 3 sections (maybe 4)
OUTPUT PROGRAMS: these will be your synthesizers. really anything that send a signal..
SERUM - SOUND DESIGN IS EASIEST ON THIS PROGRAM . More hands on experience, you get to see what exactly happens to your waveforms as they are modulated, also filtering is endless as they have well over 100 filters accessible to the user. (side note: filtering in this context would be either boosting or diminishing certain frequencies to achieve a certain sound. a good example here is to search what a comb filter is and what it does to a waveform. gaining the skill to know exactly how to make a certain sound just be hearing it takes years of constant work.)
Massive - A cornerstone plugin for dubstep production... this plugin has lots of wavetables to choose from. I find it also useful for creating snare tails, as they have a variety of white noises you can use and modulate to your personal need. you will find that even with this, you will need the skillset and understanding of what waves are, and how the modern "dubstep" sound is derived.
FM8 - More niche than most synths, often you will find this is used for melodies more so than for growls, just because as you go on you will find that using massive or serum is just plain easier in most cases, but its really a personal preference kind of thing.
POST PROCESSING: you will often use these programs to enhance your raw signal.
OTT COMPRESSOR - I don't really know what this does, but this is definitely something to use in dubstep, it makes things much more crisp, without making them sound "wide"
Fab Filter : Basic Filter. You can use it in whichever way you please.
Fruity Reverb, ValhallaRoom, Ozone 5 Reverb : All put your sound through an algorithm to make it sound like its in a certain atmosphere. You pick it, or you create it yourself. The wider the sound, the less crisp it will sound. Best used in moderation, or strategically.
Basically, this section and the post processing section are very similar, but some programs can be better classified here as they are only applied at the very end.
I only use:
OZONE 5 : This is a package that consists of 8 (i think?) mastering programs that have to do with making your mixdown louder, stronger, more punchy..
Check out some videos by virtual riot, Dodge & Fuski, and the many available sound design oriented youtube channels. Perfecting your production quality will take years. There are alot of things that I haven't covered here. The best thing to do is to just put yourself into your DAW and do your best to try to figure things out one by one.