SQL Injection tutorials?

Hello MPGH, Im wanting to learn more about SQL injections and gaining access to websites and all that good stuff. I was just wondering if you all have some great tutorials that I could take a look at? I understand that I could just google this but a lot are outdated and old and some of you may have some good ones that you like and know of.

' OR ' put that in not so professional looking forum/website shop website etc ,put it in USERNAME and PASSWORD field and click ok. It successful, you will be loggedin as a guest/or some another member of the site. Although you are not logged in but has become the guest or the member of the site , now u can post ,download member only stuff and what not.