What is lumen gentium??I need some info becauseI have to write a report on this?

Answer 1

http://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19641121_lumen-gentium_en.html

Answer 2

Here is a good link;
http://www.newadvent.org/library/docs_pa06cr.htm

as is the answer above,both will be of good use to you.