On Wed, 2013-06-12 at 13:44 +0530, Arshdeep Singh wrote:
I already have a working copy of Inkscape. How do I link my launchpad account to it ? Will I need to 'checkout lp:inkscape' again ? 

There is nothing you have to do.  But the difference between the two is using HTTP vs. SSH, which can make things faster.  You don't have to redownload to switch though, just set up a shared repository.  Let's say that I have ~/old_inkscape and I want to turn that into a new download.  You can do this:

$ mkdir inkscape
$ cd inkscape
$ bzr init-repo .
$ bzr branch ../old_inkscape old_trunk

And that will copy all of the revisions into the shared repository.  Then when you do this:

$ bzr branch lp:inkscape trunk

Bazaar will look at what revisions you need, and which ones you have, and only download then new ones.  This makes it also faster to keep your private branches up-to-date as you'll only download the revisions you need.

I was once talking to a developer who mentioned that one of his favorite features of Bazaar was that it was developed by people in Australia.  So they understood slow networks and high latency.  ;-)

Basically, I have little information on how to announce a public branch for my project.
Can anyone advise something ?

Jabier is correct here, you just need to push to a branch and LP will take care of setting it up and making it visible.

Ted