As people get more used to it, RankingsHQ will become the first place to look for upcoming events. At the moment though, I suspect that many events are only being defined on the site once its time to upload the results (this is still very much the case in the 40K world).
In addition to RankingHQ I would suggest the following resources:
For WA events, check out the Westgamer 2010 Tournament Calendar
. I didn't notice any WFB events for May, but there are a couple planned for June.
For SA events, check out the WAU Australia and NZ Tournament Calendar 2010
. It looks like there's a 3000 pt event in early June but I don't know that 3000 pts would be the best event for a beginner.
For 40K in SA there is also http://sa40k.webs.com
, which has SA 40K Tournament info. I don't know if there is a WFB equivalent.