I have a site and I want it to rank well in some of the Google country -specific sites, like, google.com, google.co.uk, google.com.au and so on. Can anyone guide me how to set geographical target for my site. Does it help to submit my site individually in Google.com, then in Google.co.uk and also in Google.com.au? Please advise.
No, you need not to submit to every domain individually. Once the site is indexed by Google, it will be visible on all the country specific domains if its content is relevant to the searched query.
Submitting your site to the main Google site that means to Google.com is enough. They will take care of the rest.
No, it doesn't. Just change the preference settings at Google Webmaster Tools under 'Geographic Target'. OR Change the domain extension instead of common TLD. Example: .co.id for Indonesia, .co.uk for UK.. Google wrote this on their GWT setting's page: Country-specific domains, such as .ie or .fr, are already associated with a country or region.