What to send us
CV
One amusing beginner's tip: you are applying for a position at a graphic studio and (especially if you are applying for a designer position) your CV should look like it. It certainly doesn't have to be a work of art, but it's the first thing where you can show that you are precise craftsmen. Oh, and we'll be glad if your photo is included too.
Cover letter
It is not strictly necessary. But you will make us happy if you can summarize in two or three sentences in the cover email why you are applying specifically to us. And where you see that your skills and our needs could meet.
Portfolio
Beware, this is the only necessary item. Put fewer things rather than more in the portfolio. What should be in it:
Ideally real projects (school work, work on free topics won't provide us with much information about how you cope with what happens at AnFas). Ideally commercial projects. Work where you were given a brief and had to deal with it. Ideally larger wholes (a logo and its expansion into other documents, a multi-page publication or presentation, a complete website - and not just a banner, etc...).
It's good to provide the works with a comment that sheds light on other important information: For example, how much of the work is yours, who else participated in the work, what the assignment was, input conditions, why you value the work, and so on.
A web portfolio is definitely a fine thing. For graphic designers, however, we like it if they arrange their presentation into one clear document too.