Having lived in Australia for nine years and had many dealings with DIMA (Dept Immigration & Multicultural Affairs) in Oz, I would strongly recommend getting your advice through an agent. I used a crowd called Consultrade based in Sydney and found the service great. Denise Jenner was the woman I dealt with and she was efficient, helpful and very informative through every stage of the visa process. I was Sydney based at the time on a succession of temporary visas applying for residency.
I'm sure there are heaps of other agents out there but if you use one, make sure they have specialists in Australian immigration issues.
My knowledge of people who applied based on the skills program is that it took a good few months to get paperwork organised and submitted and to finally hear the result but thats a few years ago now. Not sure if they process is faster these days.