I have just switched from svn to mercurial and have read some tutorials about it.
I\'ve still got some confusions that i hope you could help me to sort out.
I wonder
The main thing to remember is that branches are no longer directories in a DVCS like Mercurial (or Git).
Mercurial offers 4 branch models (details in this SO question and in this article):
The ConvertExtension uses by default named branch (but you have option to use cloned or tagged branches)
Try out some SVN to Mercurial Conversion cases, and see what works best in your case.
Once a SVN repo has been imported in one Mercurial repo (with named branches in it), you still can clone whatever branch you need in a separate repo:
hg clone -r