I read your earlier post, I suspect you're casting a broad 'net' to see what comes back, before starting research yourself, is this correct ? If so, I believe I can offer advise on how to research from Australisia.
I recommend you do the following, work on your Australian Tree first, if your family immigrated from Scotland in the 1850-60's you're only dealing with maybe 6 generations so-far.
Talk to your older relatives before they die (grin) find out all you can about their cousins/aunties etc etc, also write down all you know about your family yourself... make lots of notes.
The key piece of information you're after is the name of the original immigrant, and maybe the year he arrived in Australia, go to your local library (ask the librarian to guide you) look at shipping lists, this could involve some work, but there is no easy way to do this.
We're lucky really really, it's not a very common Surname...When you locate the passenger list with his name on it, it should also include what family sailed with him.. his wifes name, the names & ages of their children, and what port they sailed from, possibly even where they lived prior to the journey.
While working on your Australian tree, also read all you can about Scotland in the 17 & 1800's, farmilarise yourself with the social conditions, the staunch Presbyteranism, the health conditions & the appaling mortality rates for children etc, give yourself a broad general knowledge of the Country at that time in history. Also a good idea is to look at a decient Atlas, know the landscape.
For me, doing thisbackground reading was invaluable, I always wondered just why a man would subject himself, a wife & 5 children to a 4 month non-stop sea voyage. On my family's trip...even the Ship Doctor died of illness !!!
Doing the Aussie tree first gives you the skills for doing the Scottish tree later, when you have the specific area in Scotland they came from, look up familysearch.com, have a read through information. Use this sourch to get preliminary info, to confirm & check yourself later.
Once you have more specific facts & information, there are many professional researchers in Scotland who can do the work quickly & cheaply for you, using their professional skills & local knowledge. One woman who is highly recommended is Carol Wilson of Scottish Family Search (www.demon.co.uk/sfs/sfshome.htm).
Two key things I learned the hard way, the Net is full of people who love to have broad general chats about family trees etc, and offer information...but that does not take the place of proper research done by yourself, do a 'common sense' check on anything offered to you.
Also, the Net is full of real experts who can help, especially Scottish Family Search type sites..but beware, these people hate having their time wasted, ask specific questions, supplying what facts you have yourself, dates etc, and you'll be suprised..
Goodluck with your mission, Brent