There are many question that comes to your mind when one thinks of Google,how it ranks website? , why some sites are banned? In this article I have tried to answer few of these queries. If you any question you can ask me at info@varshltech.com

1.) How often Google update their SERPs
A. Google update their SERPs constantly.

2.) What are different operator /command that can be used in Google?
link:www.domain.com (returns a list of backlinks that google has indexed. Only a small selection is listed however.)related:www.domain.com (returns a list of sites that google sees as related to the topic on your page. At present, not very accurate.)
allinurl:keyword (returns a list of pages and sites that contain the 'keyword'in their url.)
site:www.domain.com (returns all pages of the domain that google has crawled and indexed.)
allinanchor:keyword (returns a list of pages and sites that contain the keyword as anchor text in their backlinks.)
cache:www.domain.com (will show the current cache that google has for the page)
info:www.domain.com (will return information that google has for the page)
allintitle:keyword (returns webpages that have the specified keywords in the title)
intitle:keyword (returns listings of webpages that have only the specific keyword as the title.)
You can find all the Operators at Google Operators

3.) Can you explain the "Sandbox Theory"?
The sandbox theory says that Google has a unique ranking element in their algorithm that has been affecting sites whose major SEO efforts began after March of 2004 (this would include all sites registered after this date). The criteria, elements and solution of the 'sandbox' have not yet been identified or publicized by the SEO community, but ongoing discussion and testing have determined that the two of the most likely issues creating the sandbox could be:
Age of backlinks - older backlinks now carry greater weight at Google
SEO specific filters - Google is actively attempting to filter sites out of their index that are actively optimizing (link-building, etc) or appear to have un-natural attributes (optimized pages, links, anchor text, etc.)
If your site is ranking well for specific keyword phrases at engines like Yahoo!, MSN & for the all in sets of searches at Google (allinanchor:, allintitle:, allintext:, etc.) but not listed in the top 50-100 results at Google, the sandbox effect may be at work. However, it is important to keep in mind that this phenomenon is an 'unknown' algorithm piece at Google and standard optimization tactics, even by some of the best and most experienced SEOs have yet to consistently beat this effect.

4.) What are things to look for if your site ranking goes down in Google listing? ( i.e. I have lost the top spot, what happened? )
A: Most obvious reason would be a drop in backlinks. Obviously when you are not aggressively acquiring new inbound links to your site on a day-to-day basis, existing backlinks may even deteriorate in value or The referring site may disappear, be changed, lose relevance or lose PR itself, reducing the PR that is passed onto you. Thus resulting in dip of your listing.

5.) Should I submit my website to Google every month?
A: No, you only need to do it once. In most cases you will not even need to submit your website to Google. If you are active in building links to your website then Googlebot will frequent your site soon, and thus include it in the index.

6.) My site is not cached in Google, I've submitted it to google numerous times but I'm not seeing it crawl my entire site. I'm also seeing an incomplete listing.
A: Sometimes the googlebot will visit, and leave, only to come back at a later time in order to crawl all of your pages. If a site has no cache, or an incomplete listing, it has not been crawled and indexed properly yet. The best thing you can do is get more in bound links to your site, so that the googlebot arrives to your site from more than 1 source.

7.) When I look up my site in Google, it is ranked #13, but when my friend in US looks it up it is #20. Which ranking is Correct?
A: They both are! Actually, a more accurate explanation is that Google using multiple datacenters that deliver the results you see. The datacenter that is used depends on your geographical location. It is very common to see a small difference in results depending where you are. Sometimes, results can differ when you move just a few miles away!

8.) Why does Google hate me/pick on me?
A: "Google" does not pick on individual sites but instead allows complex mathematical equations to decide the value of your site in any particular search. Although it may sometimes feel like they are picking on you, most times a ban or bad results can be traced to a small piece of bad or misguided SEO.

9.) Google banned my website?
A: You can check whether you are banned in Google or not indexed in Google, by using the 'site:' operator in Google's search. For instance ( site:www.yourdomain.com)