Congratulations on getting your sponsorship accepted :D
Is your agent putting your application in online or by paper? Our application went in online on the 4th Oct and we requested our police checks a week later as they take up to 40 days to come through and we had our meds last Monday (13th). Our agent recommended waiting 6 weeks before going for meds - some agents do not like you to frontload at all so it is up to you.
What you will need to bear in mind is that you will have to enter oz within 1 year from the date of your medicals or police checks to validate your visa.
I have just put some links in the visa section for meds and police checks - if your application is done online you will be able to download the forms partly completed linked to your application.
Good luck with the visa!!!