Nuno, you can do it! Just practice on something that isn't a sweater or "important" project first. Pick some yucky yarn in your stash that you klnow you're not going to use and just dive in. That chart DOES look scary
but I think if you just sit down and do it, it will turn out fine. Print out the chart and use a highlighter, that's what I'd do. I learned cables from stitch and bitch, and silver is right: they are SO easy, and people are always impressed by them becasue they look complicated! Once you do one you'll be mad that you didn't try it before.
I just tried to print the chart and directions from the website and they didn'tcome out too good, so I saved the pictures and created a word document, which is MUCH easier to read (i enlarged everything). If anyone wants it, PM me your email and I'll send it over!