To find "dotted" files -- .bashrc, .bash_profile, and so on, you'll want to tack on -a to ls (ls -a .bash*), and you'll see a directory of these files. ls is the equivalent of the Windows/DOS dir command.
I believe Linux uses dot files, so the average user won't bother with them. In other words, the files need to stay out of the way. Using a dot file is one of the ways to do that.
The .bash* files are login and environment scripts, and there are a lot of rules about what gets run, depending on whether the files are present or not. If you are strictly considered about running a program or configuring your environment upon login, modify .bash_profile. I tend to put most of my environment changes in .bashrc, because I want any other program I run to pick up the environment defined in .bashrc.