I have a blog, I checked with back link tools already with 30s back links but Google only indexed my 3 internal links ? Why so slow ? Internal links will help ? Every post I will share to social bookmark sites, will this help for back links ? Thanks
Is your blog Wordpress? You might want to install the Google Sitemap plugin, this'll make it easier for google to index your pages. As for social bookmark sites, it depends on whether or not they use dofollow on their links, but 90% of social bookmarking sites do, so yes, it does help for backlinks.
Internal linking could help your website a good flow for both visitors and Googlebots. However, please be aware that internal linking does not give an advantage for faster crawling and index by Googlebots. It just help for a good flow only. Googlebots acting weird lately about crawl / cache / index with website pages. This has happens to every websites even an authority one such as Digg.com. I would say you should not worry too much as long as your website ranking is still fine. Social bookmark can help a little for only short terms of link and traffics, should not expect more than that.