Question: I feel stupid asking, but I can't seem to find the answer to this anywhere. I'm trying to follow [these instructions](http://ubuntuforums.org/showthread.php?t=614743) to edit my bash prompt, but there is no `.bashrc` in either my user directory (`~/.bashrc`), or in my home directory, or in the main file system directory. 

There is no `.bashrc` in `/etc/` (there is a `bash.bashrc`, however). 

Do I create a `.bashrc` file in my user or home directory? Is there a better, more recent set of instructions for modifying the bash prompt?

Answer: 
There is a .bashrc in every user's home folder (99.99% of the time) as well as one system-wide (which I don't know the location of in Ubuntu).

The quickest way to access it is `nano ~/.bashrc` from a terminal (replace `nano` with whatever you like to use).

If this is not present in a user's home folder the system-wide `.bashrc` is used as a fallback as it is loaded before the user's file. You could simply copy and paste it (with root permissions of course), but a `.bashrc` is not entirely essential (it may be required to make things work. I haven't found out) at a user level as it mostly overrides the system-wide one with user-specific tweaks. You could write your own though.

The main components for that users may tweak are `PS1` (the Bash prompt defaults to display `user@localhost:pwd $`) and aliases as well as setting a color prompt and maybe `PS2` (busy state message).
Use `nano ~/.bashrc` to open and edit the .bashrc file. (This will create the file if it does not yet exist)