I just went through the RMS process and it was pretty painless. Timing will depend on whether your chosen location has a wait-list and how my are on the list waiting.
Use the interactive map from the above link to look around your desired area. e.g. right now Tambourine Bay has no waitlist, but Woodford Bay has eight people waiting.
You can also see the date the last mooring was allocated to give you an idea of turnover and any other restrictions, e.g. length/draft.
Once RMS allocates the mooring you speak with the local Boating Safety Officer to get a 'mud map' of the location so the private mooring contractor can drop the apparatus in the correct location.
There are also timing restrictions on how long you have to accept an offer and then how long you have to get the boat on the mooring.
You can call 13 12 36 (Option #2) if you want to speak to a person. I found them very helpful.