Bazaar is a distributed versioning system.

Homepage: http://bazaar-vcs.org/
Tutorial: Bazaar in five minutes, Bazaar User Guide

Most used commands

Create local branch

bzr init
bzr add file1 file2 fileN
bzr commit -m "Initial import"

Create local repo

bzr init-repo
bzr init trunk
bzr init branches
bzr init tags

Copy remote repo

bzr branch bzr://path/to/repo

This copies the branch to your local directory. The two repos are still independent.

Convert to checkout

bzr bind bzr://path/to/repo

Connects to that repository so commits are always made on both repos unless the --local parameter is given. Local commits can be merged later by bzr update followed by bzr commit. unbind removes the connection with the parent repo.

Import SVN dump file

To import a Subversion dump, use svn2bzr.py (or at LaunchPad).
You will mostly just convert the dumpfile to a big bzr-repo:

svn2bzr.py svn.dump bzr/

You can then push the repo to the central repo by issuing

bzr push bzr/ bzr://path/to/central/repo