I've read essays about Germanic peoples. These essays usually highlighted what the different German tribes had in common with each other, even though each tribe spoke a different language and lived in a different cultural area.

The same could be said about the Celts

In spite of my efforts, I've never been able to find any studies about the Italic people as a whole. Rome has apparently eclipsed the Samnites, Umbrians, etc. But what did these different peoples (Romans included) have in common? And I mean culturally, religiously, etc.? I know that Mars for the Samnites was Memerte, but I know little else. Does anyone know anything?

I think the italics never seen themselves as a whole, before the social war.

I thougth that the Romans saw people who lived in the Lazio as near relatives, but I'm not sure, I also think that at the beginning Romans didn't see the italics as his equals.

Building on Mixcoatl's language list, it is to be noted how the Romans viewed the other Italic peoples.  The Romans called all the Oscan-speaking peoples collectively as Sabelli and their language, Oscan, due to the fact that the first Sabelli they encountered in the south in Campania were called the Osci.  They viewed all Sabelli as descendants of the Sabines, and in fact, the Sabelli called themselves the Safineis.  The Sabelli included the Sabines, Samnites, Mamertini, Oscans, Bruttians, Lucanians, and Frentani, among others.   What encouraged the multiplicity of Sabelli tribes is their collective ritual called the ver sacrum otherwise known as the Sacred Spring. 

According to The Oxford Classical Dictionary, (Third Edition, 1996):

"In times of distress all produce of the spring (or the whole year) was consecrated to a deity, primarily Mars.  The animals were sacrified; the humans, when of age, were sent away.  This controlled overpopulation led by a god or totemic animals the sacrani (the 'devoted') founded new communities:"  The article explains that to a much lesser degree, even the Romans practiced the ritual, although the only recorded instance took place in 217 BC. 

Also, as a follow-up to what Mixcoatl said regarding the Venetic language, due to improved readings of the known corpus of 250+ Venetic inscriptions, we now know that not only was Venetic not an Illyrian language but an Italic language, but also that Venetic was actually closest to Latin, than to any other Italic language.  It is therefore considered a Latino-Faliscan (or Latinian) language. 

http://iranianlanguages.com/indo-european.htm - http://iranianlanguages.com/indo-european.htm

Ancient Italy was populated by Celts (Gauls) in the North West, Veneti in the North-East, Etruscan in the Centrte-North, Proto-Italics (among which the Romans and the a/m Oscans, Umbrians, Volscian, etc.) in the Center South, Sardinians in their island and Greek colonizers on the Shores of the South and Sicily.

Here you can see an interesting map:

Coming from this excellent site:

http://www.evolpub.com/LCA/VTLhome.html - http://www.evolpub.com/LCA/VTLhome.html

...where you can also find many examples and data on the languages of ancient Italy.

As mentioned yetr, the Proto-Italians (Latins, Faliscans, Oscans, etc.) seemed to be quite closely related in language, Religion (essentially pagan-animistic) and culture, while the Etruscans seemed to come from a completely different stock.

However, large contacts existed among the various people existing, and the most eveident proof of that is the fact they all used slightly different alphabets all derived from the Greek one (see again the a/m site).

[Edit]

Maybe Degredado will like this language tree, I just found on this site:

http://www.chiark.greenend.org.uk/~marisal/ie/italic.html - http://www.chiark.greenend.org.uk/~marisal/ie/italic.html

spanning from Proto-Italic to Modern Romance languages, including his native Portuguese:

                            Proto-Italic
        _______________|_________________
                |                   |
        Latino-Faliscan                               Osco-Umbrian
    ___________|__________      &n bsp;      __________|__________
   |           ; |          |                 |          |          |                     I
Italo-     S Romance  E Romance    Oscan     Umbrian   Volscian etc.
Western  _____|_____  (Rumanian)
   |     |           ; |
   |  Sardinian  Corsican
   |___________
   |                     |
Western        Italian
   |______________________________
   |                                                          |
Gallo-Romance                 Ibero-Romance
   |_______                  _______|________
   |       |           ;    |       |        |           ;   
French Rhaeto-Romance  Spanish  Catalan  Portuguese

I wasn't necessarily asking about linguistics, though I do appreciate the info given. All I wanted to know if there were common aspects of spirituality and culture amongst the italic peoples, the same way that there's a common culture and spirituality amongst celtic peoples and germanic peoples.

And Serge, Portuguese isn't really my native language, though my ancestry comes from Portugal. My first language is English.

And the map is cool!