I and some of my friends have thought of doing it.
Time wise you're fine, although, you probably will need to attend a couple training courses that go in 2 week blocks or long. The reserve is flexible but as part of our new defence strategy they dont prefer to think of results as second rate soldiers anymore. They get pretty much the same training as regular solders/sailors/air men. Once your training is over, you only have to go in every once and awhile. Best to maybe just contact them.
Remember, its not all fun and games either, if an actual war goes down, you could be called up.
Just find a job you want, click it and click through the training and read about it.
On the upside though, low price haircuts?

You may also like to look into this -
http://www.defencejobs.gov.au/education/universitysponsorship/===================================================
Military Training
All General Entry recruits into the Australian Army Reserve are required to complete the Recruit Course.
Duration: 28 days continuous
Location: Kapooka, Wagga Wagga, NSW
Recruit training is the same for male and female entrants. During the four-week Reserve Recruit Training Course you will be required to take part in physical training, weapon handling and shooting, drill and field craft. The training is deliberately challenging and has been designed to prepare you to be a soldier in today's Army. Recruits gain a sense of achievement, purpose and confidence during basic training, and on completion of the course feel justifiably proud of what they have achieved.
For more information on the content of Recruit Training refer to the Joining Instructions [http://www.defencejobs.gov.au/content/pdf/army/SoldierReserveJoiningInstructions.pdf]
Further information is also available at the Army Recruit Training Centre website.
Note: You should be aware that you must commence recruit training within 6 months of enlistment."