What is best practice SEO approach to re structuring a website with multiple domains and associated search engine rankings for each domain?

[JimmyFlorida]

Hello Mozzers,

I'm trying to improve and establish rankings for my website which has never really been optimised. I've inherited what seems to be a mess and have a challenge for you!

The website currently has 3 different www domains all pointing to the one website, two are .com domains and one is a .com.au - the business is located in Australia and the website is primarily targeting Australian traffic. In addition to this there are a number of other non www domains for the same addresses pointing to the website in the CMS which is Adobe Business Catalyst.

When I check Google each of the www domains for the website has the following number of pages indexed:

www.Domain1,com 5,190 pages
www.Domain2.com 1,520 pages
www,Domain3.com.au 149 pages

What is best practice approach from an SEO perspective to re organising this current domain structure?

1. Do I need to use the .com.au as the primary domain given that we are in this market and targeting traffic here? Thats what I have been advised and it seems to be backed up by what I have read here.

2. Do we re direct all domains to the primary .com.au domain? This is easily done in the Adobe Business Catalyst CMS however is this the same as a 301 redirect which is the best approach from an SEO perspective?

3. How do we consolidate all of the current separate domain rankings for the 3 different domains into the one domain rankings within Google to ensure improved rankings and a best practice approach?

The website is currently receiving very little organic search traffic so if its simpler and faster to start again fresh rather than go through a complicated migration or re structure and you have a suggestion here please feel free to let me know your ideas!

Thank you!

[JimmyFlorida]

After much discussion and further research here's the approach we have taken:

1. Setup all domains in Google Webmaster Tools
2. Verified ownership of all domains in Google Webmaster Tools
3. In Webmaster Tools chosen "Change of Address" specifying that the site has now moved to our chosen primary domain being the .au domain
4. Setup redirects for all old domains

If anyone can suggest any further improvements to this strategy please let me know!