Before you can start programming, you'll have to install some software on your
your machine. You're going to need a text editor to write your programs in,
and you'll need a compiler or interpreter for the language you are using in
order to run the programs that you write.
Text Editors
As a programmer, you're going to spend an awful lot of your time editing text,
so you will need a good text editor.
I personally recommend Vim, an open-source editor that you can use from the
command line (there is also a GUI version of it available). If you hate using
Vim, maybe you could try emacs. If you don't like either of these, there are
plenty of text editors out there, I just recommend trying one of these two
because they are easy to use on the command line and can be configured to do
plenty of interesting things. Both support macros and can be customized quite
a bit (using vimscript for Vim and Emacs Lisp for emacs). If you ever find
yourself doing some sort of repetitive task with formatted text (as you likely
will at some point while programming), you can create macros to take care of it.
Notice that I keep mentioning ways for you to be strategically lazy while using
your computer. Good programmers let the computer do the boring, repetitive tasks
they encounter in life. That is what computers are good at.
If you want to try Vim, just type "vimtutor" at the command line. It is
usually installed on Mac OS X and plenty of Linux distributions. You could
also type "emacs" to try the emacs editor. Whichever editor you end up using
doesn't really matter that much. Just find something that works for you that
you can edit text efficiently with.
Compilers and Interpreters
Depending on which high-level programming language you've chosen to try, you
will have to install either an interpreter or compiler for the language.
(Part of the reason I recommend you get familiar with the command line is that
tasks such as installing and configuring software are very easy to do with a
few commands.)
After you have a compiler or interpreter for your language and a good text
editor that you can use efficiently, you will be ready to start writing programs.
When you write your programs, make sure to save them with the appropriate file
extension (".py", ".rb", ".c", etc.). You'll get to this step after learning
the basics of your first programming language.