I would like someone to explain to me in simplest terms how to subnet and find subnet ranges. Thanks.:)

Unfortunately, there is nothing simple about subnetting. In my opinion

Cisco IP subnetting 101: Five things you should know
That link should get you started on the basics though.

As EOS said, subnetting is not simple. And the link he provided was a very good one - introductory and basic, with good links to get more information.

However, in my many years in networking, I have found the easiest way to always be able to quickly manage subnetting (aside from learning a few maths tricks - and with me that's generally not that quick ;) ) is to use a subnet calculator of some sort.

While there are applications available, since I never know where I am going to be and what OS I'm going to be using, I use the following website (I am in no way affiliated with this site, FYI):

Online IP Subnet Calculator

And for CIDR subnetting (more usual, nowadays)

Online IP CIDR / VLSM Supernet Calculator


I have yet to find a subnetting need that this web app hasn't solved. Hope this helps you too.