FuelPHP framework

This framework is simple and flexible and easier to study. Try if you don't have much time!
http://fuelphp.com/

CodeIgniter php framework

This framework is much simpler than other frameworks. Try it if you develop smaller systems.
http://ellislab.com/codeigniter

Cacoo: Tools for Creating Website Wireframes

Cacoo is an online drawing tool for creating a variety of diagrams. It's very useful to create website fireframes.
https://cacoo.com/

Sneakpeekit: Sheets for website wireframes

This provides lots of sheets for website wireframes.
http://sneakpeekit.com/

Mockingbird: Tools for Creating Website Wireframes

This looks cool.
https://gomockingbird.com/

Moqups Tools for Creating Website Wireframes

This is free tools. Just try and use it if you like!
https://moqups.com/

Notism

This is a great one which works well with common design tools like Photoshop, Fireworks and Illustrator.
https://www.notism.io/

Twitter API

Let's try Twitter API. 
https://dev.twitter.com/
http://www.youtube.com/watch?v=Hr19uEOQL-U

Google API

Google API is really useful. For example, you will know how useful Google MAP API is.
http://code.google.com/
http://www.w3schools.com/googleAPI/

Facebook API

Try Facebook API. It must be great!
https://developers.facebook.com/
http://www.programmableweb.com/api/facebook

How to use GitHub

When you work in a team, you should learn how to use GitHub.
https://github.com/
http://readwrite.com/2013/09/30/understanding-github-a-journey-for-beginners-part-1#awesm=~oqF51QxlBg6AUy

Zend php framework

This framework is also good one. Try if you find out this one suits your web application development.
http://www.zend.com/en/

Symfony php framework

Symfony is a powerful php framework which has useful classes and APIs.
http://symfony.com/

CakePHP

Let's see how this framework works.
http://cakephp.org/

Drupal7 Splash page

It's not necessary to build a splash page in Drupal website. But, it sometimes make a website impressive if it is well-designed.
https://drupal.org/node/1910456
http://drupal.stackexchange.com/questions/60160/splash-page-for-drupal-7-website

Drupal7 Git

Must learn how to use Git in Drupal
https://drupal.org/node/803746
http://www.youtube.com/watch?v=4zFxeND0IWE

Drupal7 function drupal_mail

This function provides a composed form of  an e-mail message and optionally sends an e-mail message.
https://api.drupal.org/api/drupal/includes!mail.inc/function/drupal_mail/7

Drupal7 function drupal_get_form

This function allows you to get a renderable form array for a particular form ID.
https://api.drupal.org/api/drupal/includes!form.inc/function/drupal_get_form/7

Drupal7 function theme_more_link

https://api.drupal.org/api/drupal/includes!theme.inc/function/theme_more_link/7

Drupal7 function theme_item_list

This function is very important when you do theming in Drupal websites. Should explore this.
https://api.drupal.org/api/drupal/includes!theme.inc/function/theme_item_list/7

Drupal7 function module_invoke

This function invoke a particular hook for a particular module.
https://api.drupal.org/api/drupal/includes!module.inc/function/module_invoke/7

Drupal7 DrupalWebTestCase

 DrupalWebTestCase allows you to use many utilities for running tests. You should use this class when you want to create a new test case.
https://api.drupal.org/api/drupal/modules!simpletest!drupal_web_test_case.php/class/DrupalWebTestCase/7

Drupal 7 function theme()

theme() takes one or two arguments:
- The name of the theme operation
- An associative array of variables to pass onto the theme operation
https://api.drupal.org/api/drupal/includes!theme.inc/function/theme/7 This function is useful, but calling the theme() function directly is strongly discouraged 

Drupal7 function module_list

This function returns an array of module names. It is very simple but useful when you want to list modules for some reasons.
https://api.drupal.org/api/drupal/includes!module.inc/function/module_list/7

Drupal7 function hook_help

You can provide help for developers using this hook. It's quite helpful when you develop a module with some other people.
https://api.drupal.org/api/drupal/modules!help!help.api.php/function/hook_help/7