First off: http://lmgtfy.com/?q=Networking+and+Telecommunications
Next, you speak of "hopefully major" which implies to me that you are either an early college student, or in highschool, considering college/career paths.
So, first thing's first. If in highschool, take a Computer Technology course if they're offered there. That should at least start you off, get the basics down. For me, I was able to take one computer tech class at my highschool senior year, and get 15 college credits (3 classes essentially) out of my way for College this year through a program called Tech-Prep. Look into anything like that.
Obviously, networking has to be done securely, so you're at the right place to at least gain a few resources as far as security goes. I don't pretend to be an expert at all, but I'm studying in college to obtain a AAAS in Informatics in Networking, and on the way to that degree (2 year degree) hope to pick up my CCNA, and perhaps some A+ certs as well.
Currently I'm in my 3rd A+ geared class, haven't taken an exam yet though.
Anyway, as far as other resources go, try grabbing a Cisco book from a teacher, or at a library, or bookstore, borrow or buy. Read up on some of that.
Hands on stuff? Get yourself an old router or modem and take it apart.
Grab some old piece of shit computers and network them together in your own Local Area Network. See what kind of fun you can have.
Personally I'm really into security, so when I and friends do that, my first priority is "okay now let's infect these things with every virus we can and see if we can eradicate them." etc. My friends think I'm nuts and get really scared about "downloading" viruses intentionally for that purpose.
But no seriously, you can do all manners of things to increase your knowledge/experience, and see if you have an aptitude for it. Education, experimentation, etc. etc.