I have noticed some new sites are coming first page for competitive keywords. They are coming first page and competite with high page rank websites in first page. How it is possible? Google helping new websites?

its not true that new site could get the high rank.because google count the back link and the behalf of them google provides the rank else there is no any site who could get rank without this fact.and if telling truth then it is possible site has the link from the relevant site that is quality link

Ofcourse , your website gets good quality of google guidelines, surely it will shows at google search page .

many new sites follow google's instructions
given in their new webmaster tools account
many older site operators think they know more than google does, about google
those older sites think they dont need webmaster tools accounts, and disappear from ser