For those who are interested in Software Testing

Here is an ebook

 

http://www.softwaretestinghelp.com/manual-testing-help-ebook-free-download/

 

and here is a blog

 

http://www.nia-testing.blogspot.in/

Karnaugh Map

Here you get the concept of Karnaugh Map explained. This can be used in writing powerful query.

http://www.facstaff.bucknell.edu/mastascu/eLessonsHTML/Logic/Logic3.html

Tutorial on SQL RDBMS Concepts

You can spend some time learning from these tutorials

http://www.tutorialspoint.com/sql/sql-rdbms-concepts.htm

MySQL Tutorials

Here is a good source on MySQL tutorial and related topics.

 

http://www.mysqltutorial.org/

Beginners PHP

Easy to learn contents related to PHP and more

http://www.homeandlearn.co.uk/php/php.html

PHP Tutorial

Good website. Easy to learn.

http://w3schools.com/php/default.asp