Is this the best way to make the max-width and centered?

Why use a wrapper unless and until you need it? I wouldn’t wrap stuff nilly-willy just because you can, it adds up. Also, you can use the Body tag as a “free wrapper” if you want:

CSS:

html {
    margin:    0 auto;
    max-width: 900px;
}

body {
    /* whatever you want */
}