If you are new to lifting weights this won't apply to you. Mostly, because anything will work for you to build strength. These are usually referred to as "Newbie Gainz". Essentially as your Central Nervous System (CNS) learns the movements and muscle patterns you'll set PR's relatively fast. Nonetheless this can still be good information for you to have.
1. REP RANGES
Let's start with the easy stuff. 1-5 Reps is your benchmark Strength training rep range. This is because of the CNS and muscle fiber recruitment that takes place during this force output. The rep range is pretty easy to manage, and is not to say that you will not gain any strength from going beyond this rep range just that it is the most beneficial.
The force output in this Rep Range is also important. If you're doing a light weight(30% 1RM) in this 1-5 rep range you won't be creating enough contraction in the muscle to build strength. You have to use heavy weights to build strength, Crazy right? This doesn't mean you have to do 100% 1rm every set either. In fact it would be more beneficial to do say 10x3 70-75% 1rm.
Lastly every rep should be performed as fast as possible. Especially during the concentric portion of the movement. Building strength requires the activation of fast twitch muscle fibers. The more explosive you are the stronger you will be. Although with heavier weights you won't be able to perform them quickly you still want to approach them with explosiveness.
This should be relatively short to cover. There's no magical number of sets. 3x5 and 5x5 systems have been around forever, I love and use them myself. That being said they aren't the holy grail of strength training. In fact with proper strength training you can really do as many sets as you want. I'd even encourage it. I've often done 10-20 sets on ONE EXERCISE. Which brings us to our next section.
How long should I wait between sets? The standard is 2-3mins, which isn't a bad guideline. I would say that's often too short. You and your muscles will likely "Feel" ready to lift again, and you may even be able to perform the lift again. However, your central nervous system has not fully recovered and that next set will feel a little tougher. If you instead give yourself 5-10mins between sets (longer is needed if you don't frequently train with heavy weights) to allow not only your muscles, but your CNS to recover as well you can hit that next set with full intensity.
1. FORCE OUTPUT
Finding your 1rm is going to likely be through trial and error. A 1rm should take 5-7secs of maximum output to complete. It will also change day to day. Depending on a whole host of variables. I would also say you shouldn't look to hit a 1rm every time you're in the gym. Although don't shy away from the periodic 1rm attempt. Find a weight you can lift let's say 8 times. The absolute most times you could lift this is 8 if I had a gun to your head you couldn't squeeze a 9th rep. Now, take that same weight and do it for 3-4 reps. This is likely right around that 70-75% 1rm mark. There are also tons of resources for charts that will tell you if you can lift "x" amount of weight "x" amount of times your 1rm = "x". These aren't bad guidelines by any means I use them myself, but I would not say they are not set in stone 100% accurate. They're just guidelines or tools. Ideally you want to train in the 70-85% 1rm range.
Overloading is a technique used to train the body for heavier loads. Essentially you take 130-140% of your 1rm, and through assistance (spotters/equipment) you complete 1-3 reps. The spotters/assistance handle the weight the the concentric part of the exercise. The lifter then exerts maximum force through the eccentric portion of the lift. Obviously, you will not be able to do this alone. Only once you hit failure should the assistance kick in or help and minimally at that. You want 100% full contraction of the muscles and activation of the CNS.