To get started with scientific computing you need to know:
How to use a text editor (such as emacs or gedit).
A bit of basic programming. There are several languages (C, C++, Java,
Fortran etc) - simply use the language you are most acquainted with (or have
the strongest desire to learn). If you have no previous familiarity with
programming, Matlab may be a good choice initially. As a student or employee
at Lund University you may download
Matlab for free (click "Logga in" and, if needed, ask
for help from a Swedish-speaking person).
How to use a plot program for visualization of your results. Again, there
are several programs for this purpose (gnuplot and Matlab for instance) -
choose your favorite one.
Below are three useful "fast-track" tutorials for getting started with
computers and numerical simulations