I believe the key to getting even decent at this game is to learn to master the keyboard short cuts. I have watched a number of video replays, and am seeing this as a must. I have only been playing for a few days however, and only just against the computer yet, so I am not really using that many. Starting this thread here so others can post their choice shortcuts, and help a brother out. So far, I have begun to take advantage of F1 which selects idle worker. Backspace which cycles camera over main bases.. Clicking on Base, and pressing s prompts to create a new worker... There are good ones for tossing units into groups. Create a group by pressing cntrl and any #. Then select that group again by pressing the number. Add units to the group by selecting them and pressing shift and same #.. Space bar advances camera to last notification, which can be good when you are getting attacked.. These are all I am using. I am however, looking for an easier way to q up builds, units, etc.. If anyone has any direction to offer on that end, I would appreciate it..
Well for me, I que up my command centers 4 and barracks 3. If the game starts to drag on and my army becomes bigger and bigger, Command becomes 5 and barracks 4 (of course the army is 1~3 or 4). Also you might want to note that ctrl + F5 ~ F8 also saves the screen that you were looking at. It's quite useful.
It is most important that you have your unit production buildings hotkeyd so you can maintain production even as you attack. I use 4-8 for this and 1-3 for my army generally. I also hotkey my command centre in the early game for similar reasons. The most effective players are almost ready to hit with a full sized army by the time their first one goes down. Of course the trick always lies in the very difficult task of splitting your attention between your base and microing your forces.
You can shift que your buildings and hotkey it on just one number btw. If you bring up the shift qued buildings and make units, it distributes evenly.
You can also hold shift to set waypoints for your currently selected units (multiple commands performed in order). I usually use this to have my scv build multiple supply depots in a row, or to have my units take a particular path to somewhere without needing baby sitting (i usually use the minimap to do this). Keep in mind that when you use it to build multiple buildings in a row it takes the money right away but you may not get the buildings for a while, so if you need money, you may not want to do this. It is also a good idea to employ this to set your workers back to mining after building something. If your just starting out I would suggest the biggest things to get comfortable is a strategy which allows you to constantly scout, maintain constant unit production, tech up when your opponent lets you and expand. Worry about the hotkeys only to the extent that they can help you get used to doing all this effectively. I can't emphasize enough how scouting is the key. Playing computers will not help you get good beyond getting you familiar with the units, just get out there and start playing in cooper league right away. Don't get complacent, if your strategy isn't working, identify the problem and change it up, it will likely be in one of the categories I listed above. Don't spend too much time watching replays unless you really have no idea how to improve your game, and even then I would suggest watching replays of people who beat you may be more useful then watching pros as your games will not be similar until you get to platinum league if even then.