Aliases are great things to make life much easier when working in the terminal. If you are getting fed up with typing cd /home/me/Desktop/work all the time, then using an aliases, you can simplify that to just typing something like mywork.
so to add your own aliases, you need to add them directly into your .bashrc file.
The format of them should be: alias name='command'
For example, this could be: alias mywork='cd /home/me/Desktop/work'
Now once your terminal session has been restarted, when you type in the command mywork, the command will be executed.