How should a fresher or a college student learn and practice good coding techniques?

- Chose the language you want to practice - Know your goal, future field - Download some free book - practice, practice, practice

For sure you must start with OOP (Object Oriented Programming) basics and techniques, because its the core of "Programming" & the core of any programming language.
then Specify the language you want first, then enjoy programming and keep an eye on the forums (of your choosen language) every day.

1 - First learn the basic programming concepts, as any programing language you'll opt for in future, will require you to have those basic concepts.
At this stage, you should even leave the Object Oriented thing.
And offcourse for understanding the basics, you'll also have to get understanding of some language, and I'll recommend the "C".2 - Once basic concepts are understood, you go for understanding Object Oriented concepts and concepts of Desktop development and Web Development.
Though in the language which you might have selected for first phase, may have OOP concepts implemented.
But in first phase emphasize on real basics, don’t try to get into too much details.
3- Now, whatever you have learned so far, try to evaluate yourself, with which programming style, you are comfortable, Desktop or Web? And which language you think you want to make your first programming language to start your career with.
Usually, a developer, works on both type of development that is Desktop and Web in his/her development career, but there are always limited programming languages, which he/she must opt for, as no one can learn each and every programming language.

Reading up on OOP and design patterns will give you a big head start.
It's surprising to see how many developers fail to grasp the fundamentals of these topics.
Also by investigating and customising a few of the many open source projects and frameworks out there for your chosen language, will help you understand what it means to write good usable code.
Choosing larger projects with a diverse community would be ideal.
Most of the time you will see that the code is well commented, formatted and tested.

It's all subjective and up-to the individual interest anyway in today's world many university teaching JavaScript as a first programming language because it's easy to grasp (without introducing DOM etc.) and later on they start with C, C++ or JAVA.
There are certain benefits of choosing JavaScript as a first native language, if one doesn't have computer science background or hell lot of passion in OO programming then it would be really though for him to start with C++ or JAVA, PYTHON etc.
Anyway today's market is quit hot and lucrative if one choose JavaScript, it's no more a toy language, now you can write JavaScript on server-side as well (NodeJS).
By the way the basic principle to learn any language is 'Just do it, do it right and then do it better'.

The best way to learn coding techniques is to write code on yourself from scratch again and again.
Start it from small programs and move gradually towards more complex programs.
Other things could be: Buy a book and and hand coded all example in the book.
Try making amendments to those examples.
Join forums such as codeproject.com, stackoverflow.com and see what people are discussing there and get helped from the experts.
Always check the manual site for whichever language you are currently being practiced.
For example if you are learning PHP do check www.php.net/manual/en/index.php frequently to see new features and techniques of implementing your desired task.
Or if you are learning .NET then go to MSDN library and search for your required topics.
Particularly talking about PHP try learning different frameworks.
Like codeignitor, zend, cakePHP, Yii and list can be more then30+.
You will learn that every framework implement their own coding techniques.
Do learn OOP (Object Oriented Programming), if you do not know OOP you can never learn good coding practice.
All modern languages user OOP so it is must to learn and you will learn many techniques learning this.
If you are web based language programmer then after OOP move to MVC (Model, View, Controller).
You will yourself know how to write good codes.
If we talk about desktop applications.
Then the methodology is the same for any language.
Just code on your own and code it in different ways.
For example you use a loop in your program and you use while loop.
Try doing the same thing with do while, for loop, for each and switch if possible.
Finally, I would say that that learning software programming is just practicing / typing codes by hand again and again or more and more.

First make sure you have the language installed with you.
there are a lot of websites that give step by step introduction to any language.
Follow them and then implement.
then try to modify them with your own ideas.
Follow the errors and try to rectify yourselves.
Eventually u will get a grasp of the language.
but all language need a lot of time to get into fingertips.

first of all have knowledge on every syntax and its use....therefore, to write coding take an example and try to implement it by knowing different logics......

For you to be a good programmer you must have a foundation of studying mathematics, logic design and data structures.
This will help you enhance you analytical skills and logical reasoning.
I would recommend you to learn C & C++ as your first programming language.
Once you learn those programming language, it would be easy for you to learn other programming languages like C#, PHP, Perl, Python.