[update] - [Contribution.md - differences of books, courses, interactive tutorials]

CONTRIBUTING.md

@@ -4,30 +4,30 @@ This guide details how to contribute to this repository.
 
 
 ## Contributor license agreement
-By submitting code you agree to the [LICENSE](/LICENSE) of this repository.
+By submitting code you agree to the [LICENSE](https://github.com/vhf/free-programming-books/blob/master/LICENSE) of this repository.
 
 
-## Everyone is welcome to add a new free book to the list
-Yep, that is true, you and your friends are welcome to add new free books to the list. And by free, we mean free, really free.
-And you know what? It's really easy, see below.
+## All the steps you need
+1. First of all, what you want to add should be actually 'Free'. Don't mistake "An easy link to Download a book" with "Free".
+2. If you don't know how to work with git or github, just simply go to [Wiki: Contribution](https://github.com/vhf/free-programming-books/wiki/Contribution) and read the rest.
+3. We have 3 kinds of lists. Make sure you know where you're adding the link:
+    
+    + **Books** : PDF, HTML, DJVU, ePub, a gitBook.io based site, a Git repo, etc.
+    + **Courses** : A course is a well designed learning material which was made by an organized group and is availabe for a long time where there is no interactive tool embeded in the site. e.g.: [OpenCourseWare](http://ocw.mit.edu/), [PHPAcademy](https://phpacademy.org), etc.
+    + **Interactive Tutorials** : An application which helps you learn, by actually typing syntax. e.g.: [Codecademy](http://www.codecademy.com/), [Try Github](http://try.github.io/), etc.
 
-
-## Steps to add a new book
- Make sure that you've read [Contribution](https://github.com/vhf/free-programming-books/wiki/Contribution), which guides you to editing a repository. Then:
-
-1. Again, unlike other projects, we prefer multiple small commits rather than one large change in a pull request - it's fine to have one pull request, but please make sure your title reflects what you've changed.
-2. Use our standard for formatting the .md file. Check it out: [Formatting](#formatting)
-3. Please try to use alphabetic order.
+4. We prefer small commits rather than one large commit in a pull request. If you don't have the time to make small commit, add an issue with all the links included and we'll add them for you.
+5. Use our standard for formatting the .md file. Check it out: [Formatting](#formatting)
+6. Please try to use alphabetic order.
 
 
 ### Formatting
-We are adults. Let's respect the next standard.
 + All lists are ```.md``` files. Try to learn Github's Markdown syntax. It's simple!
 + All the lists start with an Index, the idea is to show all of sections and subsections there, so it's important to have an index for each section. Right now it's alphabetized, so please use alphabetic order.
-+ Sections are using level 3 heading (in HTML is ```<h3>```, in Markdown is ```###```), and subsections are using level 4 (in Markdown is ####).
++ Sections are using level 3 heading (in HTML is ```<h3>```, in Markdown is ```###```), and subsections are using level 4 (in HTML is ```<h4>```, in Markdown is ```####```).
 
 The idea is to have
-+ ```2``` empty lines between last suggested book & header 
++ ```2``` empty lines between last suggested book & new header
 + ```0``` empty line between header & first book of that very section.
 + ```0``` empty line between each book in 1 section.
 + ```1``` empty line at the end of each ```.md``` file.
@@ -47,6 +47,7 @@ GOOD: * [IllumOS Dynamic Tracing Guide](http://dtrace.org/guide/preface.html) (P
 
 BAD : * [IllumOS Dynamic Tracing Guide](http://dtrace.org/guide/preface.html)- Robert
 GOOD: * [IllumOS Dynamic Tracing Guide](http://dtrace.org/guide/preface.html) - Robert
+
 ```