I am starting to build up backlinks for site and was wondering how long does it take google to recognize them. and do you notice a major difference in ranking afterwords? I realize that it could take a few links to a few hundred links to see a difference depending on the quality of the link back to your site.
do back links start to work as soon as google finds them from the sites linking to your site? or after an update?
The quality of the pages linking to yours does play a role in that. Pages that are ignored by search have very little link love to send if any. Google will need to update the page on which your link appears before it can send link love your way.
Something to consider - existing established pages on which you land a new link may not pass on much link love anyway, having your link on there from the moment a page is published might carry more weight than people think. Only Google knows.