D3.js tutorial series

A collection of short tutorials on D3.js. So far only two, but more will come :)
    var data = [30, 86, 168, 281, 303, 365];
    
    d3.select(".chart")
      .selectAll("div")
      .data(data)
        .enter()
        .append("div")
        .style("width", function(d) { return d * 2 + "px"; })
        .text(function(d) { return '$ ' + d; });
    var data = [30, 86, 168, 281, 303, 365];
    
    var scale = d3.scale.linear()
      .domain([0, 365])
      .range([0, 300])
    
    d3.select(".chart")
      .selectAll("div")
      .data(data)
        .enter()
        .append("div")
        .style("width", function(d) { return sd + 'px' })
        .text(function(d) { return '$ ' + d; });