How do I work with Branches?
To show the current branch in all Log Table Views (eg the history view and others) open the preferences and select the Appearance Tab, and check the option "Show Branch Column":
You can create new branches in MacHg through choosing the menu "Repository" > "Add Revision Label..." (Or you can choose "Add Revision Label..." in the contextual menu in the history view.) In the resulting dialog select the tab "Branch" and fill in the details to create a new Branch.
To view the information about the branch heads, you can examine the labels panel which is part of the History View:
From the labels panel, double clicking on a named branch head will take you to that branch head in the history panel above.
Or alternatively, to go to a specific branch head you can use the "go to" menu which is available in many views to go to a specific tag, bookmark, or branch:
Once you have located a specific branch you are interested in simply update to that revision and start working and you will be on that branch. See Named Branches and Branching in Mercurial for more details of what that means.
In Mercurial it is easy to work with named branches or un-named branches. (In Mercurial unlike say git one does not have to actually name short lived branches.)