There are a LOT of good books on networking theory but those for getting a CCNA qualification are good for real world examples of what you'll need to know.
One problem with the CCNA is that you have to have a network setup to do the labs. This is not a trivial expense although you can often pick up second had equipment on eBay, often from people who have attained/given up on the CCNA and are getting rid of their labs.
Another alternative is emulator/simulator software for the PC. Most of this costs but there is a free emulator called
GNS3 that is very good. I've been running this on a Linux server (it also runs on Windows and Mac) to set up various network scenarios. I had planned to get the CCNA - one day.
As previously mentioned, most TAFEs have Cisco courses and (I think) also do the exams. If you're game to do the CCNA study by yourself, you can just do the exam without sitting the course.