The word "hell" is only mentioned in the new testament, most frequently by Jesus Himself.
Matt 5:22; “But I say to you that everyone who is angry with his brother shall be guilty before the court; and whoever says to his brother, ‘You good-for-nothing,’ shall be guilty before the supreme court; and whoever says, ‘You fool,’ shall be guilty enough to go into the fiery hell.
From this verse we can glean it is a "fiery" place, where those who judged "guilty" before the "supreme court" (presumably the judgment).
Matt 5:29; If your right eye makes you stumble, tear it out and throw it from you; for it is better for you to lose one of the parts of your body, than for your whole body to be thrown into hell.
Matt 5:30; “If your right hand makes you stumble, cut it off and throw it from you; for it is better for you to lose one of the parts of your body, than for your whole body to go into hell.
From this passage we can glean it is an unpleasant place, so unpleasant that that it would be better to tear out your eyes or cut off your arm, rather than go to hell.
Matt 10:28; “Do not fear those who kill the body but are unable to kill the soul; but rather fear Him who is able to destroy both soul and body in hell.
This is a controversial verse. The "Him" (who is able to destroy) is presumably God. Some believe this verse supports annihilation-ism, others say this is an eternal/perpetual death.
Matt 18:8; If your hand or your foot causes you to stumble, cut it off and throw it from you; it is better for you to enter life crippled or lame, than to have two hands or two feet and be cast into the eternal fire.
Matt 18:9; “If your eye causes you to stumble, pluck it out and throw it from you. It is better for you to enter life with one eye, than to have two eyes and be cast into the fiery hell.
This is very similar to Matt 5:29-30; above, however this isn't the same instance, Jesus was teaching the sermon on the mount in Matt 5, Jesus is talking to the disciples in Matt 18.
But it is interesting that Jesus says this twice in Matthew.
Matt 23:15; “Woe to you, scribes and Pharisees, hypocrites, because you travel around on sea and land to make one proselyte; and when he becomes one, you make him twice as much a son of hell as yourselves.
Jesus says here, the Pharisees made their apprentices "a son of hell", presumably this means they teach them to be like the Pharisees, (ignore the commandments, embrace tradition, prefer legalism over grace and mercy)
Matt 23:33; “You serpents, you brood of vipers, how will you escape the sentence of hell?
Jesus is addressing the scribes and Pharisees again, "the sentence of hell" again seems to support this is where the guilty go after they are judged ( a guilty verdict).
Luke 9:43; If your hand causes you to stumble, cut it off; it is better for you to enter life crippled, than, having your two hands, to go into hell, into the unquenchable fire,
Luke 9:44; [ where their worm does not die, and the fire is not quenched. ]
Luke 9:45; “If your foot causes you to stumble, cut it off; it is better for you to enter life lame, than, having your two feet, to be cast into hell,
Luke 9:46; [ where their worm does not die, and the fire is not quenched. ]
Luke 9:47; “If your eye causes you to stumble, throw it out; it is better for you to enter the kingdom of God with one eye, than, having two eyes, to be cast into hell,
Luke 9:48; where their worm does not die, and the fire is not quenched.
Luke 9 here, is similar to the two passages in Matthew, One noticeably difference, is that Luke says the fire is unquenchable, Verses 44 and 46 aren't in many of the early transcripts and were added by translators.
However, verse 48 is in these transcripts, and was not added. This seems to support the idea of perpetual punishment, you never truly die in hell.
Luke 12:5; “But I will warn you whom to fear: fear the One who, after He has killed, has authority to cast into hell; yes, I tell you, fear Him!
This is similar to Matt 10:28; above. Again it is presumed that God is the one who casts people into hell.
James 3:6; And the tongue is a fire, the very world of iniquity; the tongue is set among our members as that which defiles the entire body, and sets on fire the course of our life, and is set on fire by hell.
James 3:7; For every species of beasts and birds, of reptiles and creatures of the sea, is tamed and has been tamed by the human race.
James 3:8; But no one can tame the tongue; it is a restless evil and full of deadly poison.
This passage by James appears to be symbolic, but the thought is, what we say can defile us, and "sets the course of our life". If we don't change what we say about others, our tongue will cause us to be "set on fire by hell".
2Pet 2:4; For if God did not spare angels when they sinned, but cast them into hell and committed them to pits of darkness, reserved for judgment;
Peter says hell is where the (fallen) angels are. This verse along with a few others about Hades, seems to say that hell is a temporary holding place until the judgment.
... to be continued.