I have seen many who tried their hands on linux and end up back to windows. Many students who got stuck up with the question How will I do this in Linux? which is best distro ? where to get help ? So I decided this will help those who want to try their hands on linux and who are looking for doing everything with linux.
First thing first, you can use any distribution that you want Ubuntu, Sabayon, Centos, Mint, OpenSuse, Fedora etc. these are just few out of a big list, you can check and get information about all this at Distrowatch.
But my personal advice, if you are a programmer or engineering student then try with fedora else for everyone else try ubuntu.
Now, you can get the installation instructions through web or through the home pages of distribution.
Here are some places where you can get all the information and answers to your 'how to ' questions.

There are some forums also where you can browse the solutions to common porblems and also ask some new
Fedora Forum
Ubuntu Forum
Linux Forum
Linux Questions
And if you are looking to find the alternatives for your windows softwares then try this
Alternative to
Open Site Solutions
Open Source As Alternatives
If you are looking for reasons why you should switch to linux then try this
Why Linux is Better ?
you can also google out for videos,
Usually, every linux distros has their own repositories from where you can install the packages but there is one more great place to look for some great softwares like SourceForge
For now thats all ! Please comment with more links and description so that many others get benefit ;)
Knowledge belongs to all, Follow opensource !