Buddhist cosmology unequivocally says the universe (the totality of everything) is without beginning. It was not created by a creator god, nor has it appeared from nothing in any other way. It's basically what modern science says: nothing appears from nothing, and nothing disappears into nothingness - everything is just constant flux and change: matter changes form, matter becomes energy, energy becomes matter, planets, solar systems and galaxies form and dissolve, but the matter/energy sum stays. Everything depends on causes and conditions. The best way to find out the details is not reading Buddhist scriptures (their message is how to attain happiness and avoid suffering, not describing physical science) but asking the modern scientific community.

This is just what the Dalai Lama is doing, so for many years now he has arranged yearly meetings and seminars with leading Western scientists from different fields (including several Nobel Price winners) and Tibetan scholar monks and meditators. The fascination about the meetings seems to be fully mutual, and the reports are very interesting reads - several of them are published in popular books.

Read more about the Dalai Lamas meeting with Western science:
http://www.mindandlife.org/hhdl.science_section.html
blog and news:
http://www.mindandlife.org/blog/
books and publications:
http://www.mindandlife.org/books.pubs_section.html