I bought a digital camera: Vivicam 5110 with 4 times zoom, 5 megapixels. Is this good quality or bad quality?

Answer 1

5 mega-pixels is plenty for a full page print.
The bad news is that your 4x zoom is all digital. This means that whenever you zoom in, you do so at the expense of resolution. And when you zoom in all the way, you're only using 1.25 mega-pixel. That's absolutely horrible!
If you can, I'd exchange it for something with 3x or 4x OPTICAL zoom.