Italian is a Romance language spoken by about 70 million people, most of whom live in Italy. Standard Italian is based on Tuscan dialects and is somewhat intermediate between the languages of Southern Italy and the Gallo-Romance languages of the North. The long-established Tuscan standard has, over the last few decades, been slightly eroded by the variety of Italian spoken in Milan, the economic capital of Italy. Italian has double (or long) consonants, like Latin (but unlike most modern Romance languages, e.g. French and Spanish). As in most Romance languages (with the notable exception of French), stress is distinctive.
Italians say that the best spoken Italian is lingua toscana in bocca romana - 'the Tuscan tongue, in a Roman mouth.' The formative influence on establishing the Tuscan as the elite speech is generally agreed to have been Dante's Commedia, to which Boccaccio affixed the title Divina in the 14th century.
The economic power that Tuscany had at the time, specially considering Pisa's influence, gave its dialect weight, though Venetian remained widespread in the markets and streets of the Terra Firma. Also, the increasing cultural relevance of Florence in the period of Umanesimo (before Rinascimento) made its vulgare become a standard in art, quickly imported to Rome.
The dialects of Italian identified by the Ethnologue are Tuscan, Abruzzese, Pugliese (Apulian), Umbrian, Laziale, Central Marchigiano, Cicolano-Reatino-Aquilano, and Molisan. Other dialects are Milanese, Brescian, Bergamasc, Venetian, Modenese, Bolognese, Sicilian, Sardian, and so on, essentially one per city.
Many of the so-called dialects of Italian spoken around the country are different enough from standard Italian to be considered separate languages by most linguists.
A link to an Italian site with translation features between Italian dialects and Italian: 
The sound [ŋ] is an allophone of /n/ when followed by a velar consonant, i.e., /k/ or /g/.
Italian has geminate, or double, consonants, which are distinguished by length. Length is distinctive for all consonants except for /z/, /ʃ/, /ʦ/, /ʣ/, /ʎ/ /ɲ/ .
Geminate plosives and affricates are realized as lengthened closures. Geminate fricatives, nasals, and /l/ are realized as lengthened continuants. Geminate /ɾ/ is realized as the trill [r:].
Lei and Loro (sometimes written with a capitalized L) have special meaning in addition to their meanings as "she" and "they". Lei is the polite form of tu (which is only used for individuals one is familiar with, family members, for children, or for praying to a god), and similarly, Loro is the polite form of voi (but voi or Voi too is a polite form).