Get the grill going. Go ahead and light the grill and set it up for direct grilling over high heat.
Divide your ground beef into equal portions, based on how many patties you are going to make. You want to end up with about a tennis ball sized portion of ground beef.
Now gently form each divided portion of ground beef into a tennis ball like shape. Don't overdue it, don't squeeze it, just get it into shape.
Once you have your ground beef balls, gently flatten each ball to make your patty.
Now here is a secret. You have probably experienced the "bloat" phenomenon I mentioned above that makes most inexperienced grill masters try to flatten that patty during grilling. To lessen the bloat, simply use your thumb and create an indention in the middle of the patty before you put it on the grill. It doesn't have to be too dramatic, just a little indention like you see in the photo above.
For seasoning, I also suggest that you don't over-think this one. Sure, there are many variations to the typical burger that will knock you off your lounge chair, but you've got to walk before you run! Once you can cook a decent, simple burger, I give you permission to get crazy, but let's master this basic burger first. I personally think that adding onions or other veggies to your meat classifies as meatloaf, not hamburgers, but that's just me (and besides, meatloaf is good as well!). Keep it simple for now, a little Kosher salt, some fresh ground black pepper and perhaps a little garlic powder and you are good to go, just gently rub the seasoning into your patties. Note that I can't seem to resist filling depressions or voids in meats, so you will see some Worcestershire sauce in the indention in this photo, I give you permission to do that if you must :)...
Ok, the fire is lit, your meat hasn't been worked over too hard (other than a dent in the top) and you lightly seasoned your ground beef. Carry those bad boys out and slide them onto the hottest part of the grill. Our goal here is to sear the outside of the hamburger to form a great crust, while keeping the insides nice and juicy. Take note of what time you put them on the grill so you can time this exercise.