adding search icon to input box

Here's the CSS code that I'd use:

#add {
  padding: 17px;
  padding-left: 55px;
  width: 300px;
  border: 1px solid #f5f5f5;
  font-size: 13px;
  color: gray;
  background-image: url('http://i47.tinypic.com/r02vbq.png');
  background-repeat: no-repeat;
  background-position: left center;
  outline: 0;
}

Note: I added a lot of extra codes to make the search box look better, the necessary code to make the search box apear is padding-left, background-image:url, background-repeat and background-position. Replace "http://i47.tinypic.com/r02vbq.png" with whatever search icon you want.

It's also important to know that now in HTML5, most browsers render

<input type="search" results>

with a search icon. The input type search makes it a search box, with a "x" button to clear, and adding "results" also displays a search box. Of course you could also add an x button with CSS and JavaScript to a regular search box. It's also important to note that input type search allows very little styling. Demo on Safari on a Mac:

Tell me if this helps you, and make sure to mark as the answer. :)

There's a step by step on kirupa.com here: http://www.kirupa.com/html5/creating_an_awesome_search_box.htm

With relevant bit of CSS for you here:

input[type=text] {
    width: 260px;
    padding: 5px;
    padding-right: 40px;
    outline: none;
    border: 2px solid #999999;
    border-radius: 5px;
    background-color: #FBFBFB;
    font-family: Cambria, Cochin, Georgia, serif;
    font-size: 16px;
    background-position: 270px -10px;
    background-image: url('http://www.kirupa.com/images/search.png');
    background-repeat: no-repeat;
}

Put the image into the span, for example using background-image, then give it a relative position and move it to the left so it overlaps the right end of the search box, for example:

#g-search-button {
  display: inline-block;
  width: 16px;
  height: 16px;
  position: relative;
  left: -22px;
  top: 3px;

  background-color: black;  /* Replace with your own image */
}

Working example on JSBin

Note: This is not my answer, i've found it here