Have a look at the Great Walhalla Alpine Trail website ~
http://www.greatwalhallaalpinetrail.com/ It is a guided walk, but you can certainly use the website for photos, maps and ideas.
Dont forget that who ever drops you off at Baw Baw will need wheel chains to enter. The road from Moe to Baw Baw via Erica is the best way to drive. It avoids the very windy road through Neerim.
If you are staying at Baw Baw before you leave, you can book accom at
http://www.mountbawbaw.com.au If you want to stay in Walhalla once you arrive, check out
http://www.visitwalhalla.com/Go in August and see the Walhalla Vinter Ljusfest. Paddy O'Down concerts on Wed nights, historic train rides on Sat night and heaps more.
You have picked a great walk and an amazing time to do it
Good luck
Cheers
Sue