Align Labels And Inputs

[jo15765]

How do I align my labels and inputs?

<div class="input-group">
    <span class="input-group-addon">First Name:</span>
    <div class="col-sm-4">
        <input for="fname" class="form-control" id="first_name" arai-describedby="fname" placeholder="Enter First Name" />
    </div>
</div>
<div class="input-group">
    <span class="input-group-addon">Last Name:</span>
    <div class="col-sm-4">
        <input for="fname" class="form-control" id="first_name" arai-describedby="fname" placeholder="Enter Last Name" />
    </div>
</div>
<div class="input-group">
    <span class="input-group-addon">Email:</span>
    <div class="col-sm-4">
        <input for="fname" class="form-control" id="first_name" arai-describedby="fname" placeholder="Enter Email Address" />
    </div>
</div>