Listing
To see a list of current buffers, I use:
:ls
Opening
To open a new file, I use
:e ../myFile.pl
with enhanced tab completion (put set wildmenu in your .vimrc).
Note: you can also use :find which will search a set of paths for you, but you need to customize those paths first.
Switching
To switch between all open files, I use
:b myfile
with enhanced tab completion (still set wildmenu).
Note: :b# chooses the last visited file, so you can use it to switch quickly between two files.
Using windows
Ctrl-W s and Ctrl-W v to split the current window horizontally and vertically. You can also use :split and :vertical split (:sp and :vs)
Ctrl-W w to switch between open windows, and Ctrl-W h (or j or k or l) to navigate through open windows.
Ctrl-W c to close the current window, and Ctrl-W o to close all windows except the current one.
Starting vim with a -o or -O flag opens each file in its own split.
With all these I don't need tabs in Vim, and my fingers find my buffers, not my eyes.
Note: if you want all files to go to the same instance of Vim, start Vim with the --remote-silent option.