It will depend on the site, best way to make google notice about your new content would be building some backlinks to it, specially social bookmarks and social signals such tweets containing your URL and retweeting them. But keep in mind "crawling" doesn´t mean "ranking", google robots will visit your site, and if your content is unique, google will index it (or not), but for ranking it you will have to do some Offline SEO (building quality backlinks) to it, and make sure you have a ok Onsite SEO done on your site. Best wishes.