I expect your fairly young - late teens/early twenties? So I frame my post according to the afore mentioned assumption.
[Edit apologies I just checked your profile - but post below is still applicable]
IT is a general term that encompasses a hell of alot.
Some of the roles or directions you can take:
Help Desk
PC Support/Technician
Networks - LANS/WANS and Wireless (Microsoft, Novell and Linux/FreeBSD to a lesser extent)
Network Administrator (play God on a company LAN scale hehehe)
IT Security
E-commerce (linux/FreeBSD focus) ties in with IT Security
Multimedia (tougher area to get work in - bit of a niche market I guess, depends on the locale you reside I suspect)
Developing (heavy emphasis on code naturally)
Information Systems and Analysis (aim for that cushy Bank job

)
Education/Teaching (at TAFE level that requires Certificate IV in work place Training and Assessment - which I've done - worth considering down the track)
Thats just some of the area's in IT you can look for. I expect your doing something similar to what I did in certificate IV Networks. Focus on Cisco, Linux and a bit of Management/IT Support stuff.
Since your just starting out some suggestions.
Consider doing some of these certificates while your studying your course. Bit of a tall ask - but in long run makes things easier.
I'd say go for the CompTIA A+ certificate, consists of two exams - and their adapative exams from memory. Tests you on PC Mainatenence and so forth - you can find revision material in the shops or online (
www.cert21.com). A+ is not a real demanding exam if your reaosnably familar with pc maintenence and networking some basic revision and preperation should see you pass. Bear in mind these certifications are external and cost money (approx $240-250) so it pays to pass the first time.
Other CompTIA certs - are Networks+(handy to have), Server+ and INet+.
As others have said round out your knowledge, being a specialist in one area will help you not at all! Companies and workplaces expect alot more from IT staff these days.
Probably the most important qualification you can get I expect they will be teaching you Cisco semseters 1 through 4 in certificate IV-DIploma level. Is the CCNA (Certified Cisco NetWorking Associate). Deals with the OSI Network Model and the TCP/IP Model and LAN/WAN, wireless networking technologies. Exteremely beneficial to have for employment oppurtunities and you'll also pick up alot in the CISCO course that will be extremely useful in most other areas of IT; and you'll need it!
When it comes to coding C++/VB (or VB.Net now) and Java - java is the one you really want to learn but it's also beneficial to learn the others.
Some other suggestions to think about, the big problem of course is getting experience you'll be in a bit of a catch 22. They'll want people with experience but how you spose to get some if they don't give it to you, sort of thing.
You might want to consider joining a local Linux user group/society. The Sydney one is called SLUG (Sydney Linux User Group)..lol I just wanted to say that. As well as being able to pick up help with using Linux/FreeBSD type software it will be a good way to get to know people who already work in IT areas. Because the best way you'll get work in IT is through somebody you know who already works in that area.
And don't join the military full time to just to get expereince in IT?? Sheesh. If your seriously considering that - I suggest joining the reserves first either the RAAF/RAN reserves. At least that way you can get a taste of what the military is like and pick up some experience along the way. Also note - that Australian Defeneces forces are rejecting a high number of applicant - I forget the figures, and the forces are close to reaching capacity. It's also not just likely but almost certain you'd be deployed OS given the current focus of Australian Foreign policies.
Also signup to an IT news Letter like TechRepublic often handy for picking up tips/information.
Best of luck any other queries reply here or PM me - your welcome.
All humour aside seriously peruse the site below - give you an idea of some of what working in IT really means.
ITHell