As for the first one.
US friends and acquaintances of the four alleged pilots and the two muscle hijackers (Nawaf Alhazmi and Khalid Almihdhar) who arrived first were interviewed and you can find them around the net.
For example
(1) Bert Rodriguez trained Ziad Jarrah in self defence;
(2) Anne Greaves knew Atta and Alshehhi from flying lessons;
(3) Aukai Collins knew Hani Hanjour in Arizona.
Just google their names and the interviews should come up.
The three hijackers who were in Germany (Atta, Al Shehhi and Jarrah) knew lots of people there and they have been interviewed, for example Aysel Senguen, Volker Hauth and Dittmar Machule.
Of the 17 alleged families, AFAIK only those of Jarrah (in Lebanon) and Atta (in Egypt) have spoken extensively to the media. The two UAE families have said absolutely nothing, and Banihammad's may not even have been interviewed for the 9/11 Commission report. Of the Saudis the families of the Alshehri brothers has been interviewed a couple of times, as has Al Nami's father. Alleged friends of some other hijackers, for example Ahmed Al Haznawi and Saeed Al Ghamdi, have spoken to the few English-speaking journalists allowed into Saudi Arabia. The father of Nawaf and Salim Al Hazmi gave a press conference after 9/11 but reporting on it was very patchy in the English-language press; the same applies to just about everything else in Saudi. Sometimes snippets can be found on Arab News or at the Saudi Information Agency, but not much. Moqed's family held a celebration-type funeral after 9/11 that was broken up by the police and are apparently heavily involved in opposition to the Al Sauds, so I guess the Saudi authorities will never let them be interviewed.
The 9/11 Timeline has a section of The Alleged 9/11 Hijackers, which you can find here:
http://www.cooperativeresearch.org/project.jsp?project=911_projectIt's got lots of good stuff.
You could also try Wikipedia, which is not bad sometimes.
As for the second one, AFAIK only Abdulaziz Alomari (AA 11) had a child (a baby girl, as far as I can tell she was 28 months old on 9/11). In addition to him, Marwan Alshehhi (United 93) was married. Jarrah was sort of married to Senguen and maybe Mihdhar was too (married I mean, not to Senguen).
Briefly:
Politics made them tick.
They knew they were on a suicide mission, but most of them probably didn't know all the details.
Most of them seem to have met each other working as security at Kandahar airport.
They weren't particularly devout. Al Qaeda is a political movement dressed up in religious language.