Does anyone here have any tip or tutorials how to begin with sql injection, i heard alot of website are vulnerable by it. Even very big ones, the only problem is i dont know where to begin, any clue ?

Thanks in advance.

Ok i found some i readed this and it helped me out quite good (http://www.securiteam.com/securityrevie ... 1P76E.html (http://www.securiteam.com/securityreviews/5DP0N1P76E.html)) If anyone is intressted this is handy.