So I've been playing through the campaign over the last few weeks, this being my first proper RTS outside of Brutal Legend which hardly counts, but I've really had ambitions of getting into the multiplayer since watching Brad play it live (Well, archived anyway) is what got me hooked on Starcraft II replays,  which lead to me getting the game. In less than a week I went from dismissing Starcraft II as being of a genre I had no interest in, to spending  hours upon hours watching replays thanks to seeing not only how enthralling the multiplayer is, but how Brad was able to become competent over time. So tonight I decided to give the online a proper go (Though I had lost horribly to a friend who decided to proxy a pylon in my base), going into a practice league match with a written down build order and all the knowledge I had attained from watching a ton of replays. 
 
After a 20 minute match in which I tried to adapt my build order slightly to adjust for Practice league conditions, forgot to upgrade either of my bases to Orbital Commands, and couldn't stop my hands from constantly shaking, I managed to secure my first victory on the internet. So glad I won too, great for my moral and confidence, though I imagine a defeat is in the cards still considering the sloppiness of my playing. Through that match I see I've managed to do well enough, but I see, watching the replay, many ways to improve my game, the best of which possibly being refining my Control Group use. Basically, I used 5 for my CCs, 6 for my Barracks, and 7 for my Starports (Chose against using my factory, though probably should've done considering my surplus resources. Some tanks would be nice in future matches)  My army and my Vikings went without control groups for a few reasons, one going through the campaign I found it annoying to constantly add the new units to the group to make sure they were on board, two I'm never sure how I want to separate out my army particularly if I'll just end up moving them together anyway, and three since I don't know what to do I end up doing nothing. 
 
Since what I feel like it is key in SC2 to have a system at all times such that it eventually becomes muscle memory, I'd like to ask you guys how you organize your control groups. Doesn't matter what faction you prefer, probably going to be trying them all out properly until I start to develop a feel for one. Thanks.

6 Nexsus 
5-4 Unit producing buildings (IE, Robo bay, Stargate.  Warpgate is W, obviously) 
 
1-3 army (1 for main, 2 or 3 for support units) 
 
I tend to put my Forge on 9.  When I get obs, I tend to put them on 7 and 8.

1 main army (zeals,stalkers,immortals)
2 collosus(i like to micro these to stay at max range)  
3 air
4 support (sentries or high templar usualy) 
5 nexus
6 robo
7 stargate 
8+9 = tech (forge, robo bay) 
0 = scout (probe to start with, then an observer)
warpgate is w

5 = Base
4 = Floating for random shit
3 = Production
2-1 = Control groups

For Zerg, they're pretty much dedicated to any Hatchery, Lair, or Hive that I have. Infestors get one as well if I end up making them. 
Terran I have 1 set to my main base. 2 is for my Reactor Barracks, 3 and 4 occasionally are set to Reactor Factory/Starport, and the rest generally remain empty. When using Terran I have a habit of not using Control Groups very often if at all. Zerg I find my self having to to keep up with larva production.  If I have any Infestors, Ghosts, or other ability heavy units on the field I'll give them their own as well.

1 - Whole Army
2 - Ground Units
3 - Air Units
4 - Command Center
5 - Barracks
6 - Factory
7 - Starport.
0 - Walling supply depots
I could probably be a lot more efficient, but it's what I've got used to.

1-whole army 
2-5 control groups (air, ghost, ground,tanks, etc..) 
7-barracks 
8-factory 
9-starport 
0-command center

1 - whole Army  
2-3 - Army individual units 
4 - Production buildings 
5 - Command Center/Nest 
6 - Upgrade buildings 
7 - Unit for building supply

1) Army with main abilty
2) Army with 2nd ability
3) Air army
4) Buildings
5) Command Centre
6) Worker
7) All workers except nr.6.

1) Main army 
2) Support units (Medivacs, Raven) 
3) Barracks w/Reactor 
4) Barracks w/Tech Lab 
5) Command Center

You can stick all your unit producing buildings on one key then use TAB to switch between them, same with armies

1 - Army (bulk of army usually) 
2 - Army (medivacs, vikings, hellions)
3 - Army (casters)
4 - Starports
5 - Barracks
6 - Factories
7 - Orbitial Commands
8 - Engineering Bays/Armories (normally forget to do this one)

1) Ground Units
2) Air to Air units (usually Vikings)
3) Banshees
4) Command Center
5) Barracks
6) Starport
7) Factory
8) Eng. Bay
9) Armory

Depends what setting you play on, some people play on the grid style, where the hotkeys are mapped to a grid layout and thus putting your CCs/Hatches at 1 is alot more useful as you can just spam 1qqqqqq instead of 6qqqq.
 
I use what most of these guys use which is 1 and 2 being respective armies (land/air) 3-5 is production and 6 is my CC. However, I'm slowly changing to use 4-5 as production (All reactor buildings on 4, all techlabs on 5, this is because Terran macro is kinda stuffed as the unit priority for reactor units is kinda buggy/annoying) so we'll see how that goes.

Really depends on the strategy i'll be going for. But this is what it tends to be in genearl. 3 is always my nexus, and 4 - 6 tend to be production. 1 -2 become my main army, and i'll set any micro heavy units to 2, while the bulk to 1. 

1-2  army
3 Hatcheries
4-0 Queens
 
To spawn larva I just press 44 v click 55 v click 66 v click.....
 
Only problem with this setup is the lack of unit hot keys, I use tab to get to different units for the most part

Before i stated watching some strategies, i didn't even know you could group buildings. But even so, 1 is my main force, 2 is usually med-vacs and ravens, 3 is/are my command center(s).

1 - Main army (zerglings, roaches, ultralisks etc) 
2 - Ranged/support (hydralisks usually, or banelings) 
3 - Air/support 
4 - All hatcheries 
5 - 7 - Queens