Oh my goodness. Here we are...the difficult bit. No, not really.
You want to arrange your collection so that it looks more professional and things are easier to find.
It's much easier to do so than it used to be with an online service like Librarything.
First of all decide how are you going to organize your library.
Library of Congress?
Librarything can sort your books for you according to LCC or Dewey. You can also tag your books in Librarything according to whatever description you want to give them. You can give them lots of tags, not just one.
If you wanted to arrange your books as per the Society of Australian Genealogists or QFHS classification scheme then that might take a bit more time. You would need to add the call number as a separate field of information but would then still be able to sort it by that column once you had exported it as an XML file.
Some people have left comments on this blog recommending Calibre for an electronic collection. I haven't got my head around Calibre yet but I thank them for sharing this with us. Don't forget when you don't know how to do something, there will always be a YouTube video somewhere to help!
Why don't use tinycat and make your collection searchable online? That way you won't have to worry about buying duplicates. Read more about it here.
Most importantly you should organise to interview elderly relatives as soon as possible. You will need to be organised when you do this and there are many great publications to help you in this task.
I have a book called Once Upon a Memory: Your Family Tales and Treasures by Jean Alessi....but there are hundreds of sites online to guide you through the process with suggested questions. Oral History Australia's website is here.
O what a beautiful morning! O what a beautiful day!