The Second Vatican Council met from 1962 to 1965 in four sessions (October-December 1962, September-December 1963, September-November 1964, and September-December 1965). Sixteen major documents were produced: two dogmatic and pastoral constitutions, nine decrees and three declarations. The authoritative Latin text of each of these documents can be found in :
Norman P. Tanner's Decrees of the Ecumenical Council
Available at Lemeiux Library : BX 825.A1990 v. 1 & : OR on the Vatican website
There are at least five English translations of the sixteen documents; in addition there are other English translations of individual documents. The variety of ways in which the documents have been dealt with by translators shows the necessity of referring to the authoritative Latin text.
Weblinks to the four major constitutions; arranged by date promulgated: