Try Bodybuilding.com.
A good beginner program I've heard if Mark Rippetoes 'Starting Strength'.
If you google 'Bicep exercises bb.com' or 'Triceps exercises bb.com' one of the first results should be bodybuilding.com.
If you click it it will take you to a page showing a list of exercises for that muscle part and there are filters to the side you can use to narrow down your search.
The main muscles you should always target and train are Chest, Biceps, Triceps, Legs, Back and Abs.
There are Compound exercises and then there's Isolation.
Isolation is an exercise where the weights only target one muscle, compound is when they target multiple.
Bicep curls are isolation, and deadlifts, which target legs, lower back and a bit of shoulders, are compound.
Start with a very low weight you could easily lift.
The idea is to get a feel for it and make sure your form is at least 90% correct.
If you're worried your form is bad because you can't see yourself doing it, you can ask for help at the gym, or find a mirror at the gym or if you're working out at home record yourself doing it.
The exercises on the bodybuilding.com website will show you the correct form.
Once you have perfected your form, move up to a weight you think you could do with still near-perfect form. Make sure it's at least a moderately challenging weight.
If you cannot do the weight with at least 80% good form, it is too heavy. Take off 1-2lbs of weight.
As you may already know, diet is important.
Gaining muscle is about 80% diet, 10% weightlifting, 10% sleep and other things e.g. drug use, alcohol, etc.
Why are you worried about hurting others?
The only reason you might drop the weight or accidentally be swung across the room by it would be if your form is very bad and the weight is far too high.
Just start very low on the weights so it would be impossible for this to happen.