Is that £600 UK? I'm in a similar boat to you (building for the first time). What got me sold on the idea was this article, which might be a handy starting point:
http://www.rockpapershotgun.com/2013/06/14/build-a-next-gen-pc/
I then went and discussed the matter on the GameFAQs PC Hardware board and got some very useful advice, so I recommend asking questions there:
http://www.gamefaqs.com/boards/2000403-pc-hardware-discussion/67313297
One of the people there suggested an interesting build to me, so I set up topics on GameFAQs and here to get responses. Only did it just now so haven't heard anything yet so here's a link
http://www.gamefaqs.com/boards/2000403-pc-hardware-discussion/67746779
http://www.escapistmagazine.com/forums/read/538.833239-Rate-a-mid-power-PC-build
If you are in the UK, that partpicker site (http://uk.pcpartpicker.com/) looks handy as it seems to compare prices on parts and indicate whether there are likely to be any compatibility issues (don't know if it's 100% accurate but it's a start). It also has some videos of putting some together, which made things look not too hard.
Edit: Sorry, missed the AU part. That build costs £500 UK so maybe $850 AU(?), but I've no idea how prices compare over there. Hope some of the information is useful all the same.