Here’s a list of various ways following which you can get a linux distro:
The best way, if you have unlimited internet (broadband) access, is to download the ISO image (usually 700 MB in size) from the website of the particular linux distribution and burn it on to a CD or DVD (in case of a DVD image) to install linux. e.g. visit http://www.ubuntu.com/getubuntu/download to choose and download the particular version of Ubuntu for your requirement. For other distros just google their name with “download” (though I highly recommend Ubuntu for beginners).
If you don’t have full unlimited internet and have free night downloads or some similar plan for your broadband connection (like me), then you may consider using a download manager like GetRight or FlashGet using which you can resume or continue downloads at desired times.
Request for free CDs (only available for Ubuntu and its siblings Kubuntu and Edubuntu). I warn you that they may take more than 2 weeks time to deliver the disks, but I preferred this method when I had a slow and non-unlimited internet connection.
Check your local computer hardware/software market to buy linux CDs or DVDs or buy them from an online store (can be found using website of the distribution).
Cheapest and fastest way: If you live in or near Ghaziabad, you can also contact me to get a linux CD or DVD. Various distributions are available. Just drop me a message using “Contact” link on the above navigation bar.