Yes, that's a Dob.
Dobsonian refers to the type of mount that the scope is on. It was originated by John Dobson of the Sidewalk Astronomers (you can google them) in San Francisco.
It is a very easy mount to use and I would say a vast majority of
visual amateur astronomers (as opposed to
astrophotographers) use a Dob.
With an 8 inch you will be able to see lots of stuff from planets to galaxies and nebulae, star clusters etc. You'll be able to see them with the 6" as well but the view will be better in the 8".
But realize that they won't look like you see them in glossy magazines and books, it's photography that produces images like that.
Visually through the telescope they will be fainter and fuzzier, but you'll definitely be able to see heaps of objects, especially from a
dark sky site.
I don't know where you are in Melbourne, but if you can, join your local astro society, or attend one of the various star parties they hold.
Here are a few links...
http://www.mpas.asn.au/ (this website doesn't seem to be working properly at the moment)
http://www.asv.org.au/
http://svaatest.site88.net/
http://www.astromelb.i.net.au/index.htm
As for eyepieces, the scopes usually come with a couple of eyepieces, but you'll have to clarify this with the seller.
Also, something called a Telrad finder is a great accessory to have. It is invaluable for finding faint fuzzies. You will find them at the Bintel website.
I might also add, get yourself a planisphere, and if you (or someone in your family) have a pair of binoculars, get yourself comfy (a banana lounge is great) and start with those, and you'll need a torch with a few layers of red cellophane over it to see with. White light will ruin your dark adapted vision.
Check out the astronomy section at the local library too.
That's all I can think of at this late hour.
Hope this helps