you need to increase backlinks to your site. Google will crawl your site, but will not add it immediately. Over time they will add pages, however the more (more in terms of quality or quantity) backlinks you receive the quicker they will release the pages into the index.
If you haven't already, sign up for google webmasters tool to see a better analysis of your pages indexed and the number of backlinks in google. It has some other nifty features as well.
I wish that were always true. I have 20,000 backlinks. Yet sometimes new pages take 3-4 weeks to make it into Google's index. And whenever I add a new page, I feature a link to it on my PR5 home page, and I update and resubmit my sitemap.xml. So there's no doubt that Google quickly discovers the new page. But it still takes some pages weeks, not days, to get into the index.