Muscular strength can (and should) be increased in two directions: power and endurance. Power is how much you can lift, endurance is how often you can lift it. Power is increased by lifting heavier weights for fewer reps, endurance is increased by lifting lighter weights for higher reps. Muscle soreness, which is related to trauma but is not the trauma itself, comes from a build-up of lactic acid which is a byproduct of anaerobic energy production. The muscle trauma, from which comes muscle growth, is actually microtear(s) in the muscle, which, when they repair or knit back together, are stronger than the original untorn muscle, much like a weld in metal is stronger than the previously unwelded metal.

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Muscular strength can (and should) be increased in two directions: power and endurance. Power is how much you can lift, endurance is how often you can lift it. Power is increased by lifting heavier weights for fewer reps, endurance is increased by lifting lighter weights for higher reps. Muscle soreness, which is related to trauma but is not the trauma itself, comes from a build-up of lactic acid which is a byproduct of anaerobic energy production. The muscle trauma, from which comes muscle growth, is actually microtear(s) in the muscle, which, when they repair or knit back together, are stronger than the original untorn muscle, much like a weld in metal is stronger than the previously unwelded metal.

Muscle are sore when they are used, but are not accustomed to being used. (There’s some acid which builds up in unused muscles, or something like that.) If you work them often, they won’t be sore, but they will grow. If you sit around and let them get weak and flabby, and then over-use them, they will get sore, but probably won’t grow much.

And: you didn’t mention steroids, good for you. Steroids can have incredibly serious side effects, ruin (or cut short) your whole life.

Your soreness level should not determine how hard, or how not hard you think you worked out. Work out at a level that feels comfortable for you. You will see results. If you push yourself to far, you risk injuring yourself, which will surely set you back and it will take you even longer to get those big muscles.

I always do it till it hurts.

If I don’t feel anything then I’ll do some more

and what ever your doing (in terms of lifting) go slow