Where does the Devil live? Does he have family?
They are usually invisible to humans, but humans do appear clearly to jinns, as they can possess them. Jinn have the power to travel large distances at extreme speeds and are thought to live in remote areas, mountains, seas, trees, and the air, in their own communities. They are mostly to be found in ruins and unclean places like bathrooms, dunghills, garbage dumps and graveyards
jinns also reside in toilets and that's the reason why the Prophet taught us the dua before entering the toilets:
اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْخُبُثِ وَالْخَبَائِثِ
O Allah, I seek refuge with you from all evil and evil-doers.
Yes Jinns do live in families and communities
And [mention, O Muhammad], when We directed to you a few of the jinn, listening to the Qur'an. And when they attended it, they said, "Listen quietly." And when it was concluded, they went back to their people as warners. Surah Ahqaf 46:29
More information on this topic can be found here: The World of Jinn and Its Secrets
They live in earth and around earth. But we do not see them. But they can see us. They are around us but in a parallel universe that we cannot see them usually. Those who are pious can see them. Quran talks about seven skies and earths like them. Perhaps these earths are some parallel worlds that one of them is for life of Jinns.
According to this verse it can be concluded they marry and so have family:
فِيهِنَّ قَاصِرَاتُ الطَّرْفِ لَمْ يَطْمِثْهُنَّ إِنسٌ قَبْلَهُمْ وَلَا جَانٌّ
In them are women limiting [their] glances, untouched before them by man or jinn - http://tanzil.net/#55:56
The logical conclusion of this verse is that they marry and so have family.
Evil Jinns are Satan and Iblis is a specific Satan who is the boss of all Satans and he is who God ordered him to do sujud for Adam but he refused. He is alive still. They have long life and can have life to thousands of years.
Like humans they are both good and evil. There are believer Jinns and Kafir Jinns:
And among us are the righteous, and among us are [others] not so; we were [of] divided ways. http://tanzil.net/#72:11
kafir Jinns support evil humans. For example by revealing them some information that humans usually cannot have. For example revealing information about what will happen in future or where is a lost thing. But this kind of accessing some information about future is not easy and usual for them. But in some exceptional cases they can get some information about future. Although this action is banned for them and is a sin for them and is done by Kafir Jinns.
Except one who snatches [some words] by theft, but they are pursued by a burning flame, piercing [in brightness]. http://tanzil.net/#37:10
And we used to sit therein in positions for hearing, but whoever listens now will find a burning flame lying in wait for him. http://tanzil.net/#72:9
But this is not easy for them:
And we have sought [to reach] the heaven but found it filled with powerful guards and burning flames. http://tanzil.net/#72:8
Perhaps it is like job of human hackers who access information of bank servers.
And do not eat of that upon which the name of Allah has not been mentioned, for indeed, it is grave disobedience. And indeed do the devils inspire their allies [among men] to dispute with you. And if you were to obey them, indeed, you would be associators [of others with Him]. http://tanzil.net/#6:121
The can go to other skies and access the secret information for evil purposes like magic,...
Except one who steals a hearing and is pursued by a clear burning flame. http://tanzil.net/#15:18
The fourteen infallibles have servants from Jinn that serve them. For example they deliver a letter quickly to a distant place before the ink is dried. Jinns can pass the time and place quickly.
A powerful one from among the jinn said, "I will bring it to you before you rise from your place, and indeed, I am for this [task] strong and trustworthy." http://tanzil.net/#27:39
THE devil? As in the one that was once called Iblis? That is not known.
If I'm not mistaken, 'Jinn' (pronounced as 'Djin') means 'hidden one'. Some Jinns are evil and they are devils. As for them, there's a verse in the Quran which says they reside in a place where you can't see them: http://quran.com/7/27 I'm not sure if that should be taken literally, though.
There are good Jinns who have families. I have read hadith to this effect but I can't find it, right now.
It's possible that the evil Jinn also have families but I haven't read anything to that effect.