You need to use two tags to get the EE js calendar to show up on a template. 
{exp:cal_saef:head} - this tag calls the javascript.  I’d recommend putting it in the head, but it’s not absolutely required that you do so:

<head>
     <title>
     blah blah blah...
     {exp:cal_saef:head style="yes"}
</head>

The tag has three parameters:

style - if set to ‘yes’ it will go ahead and style the calendar for you using the same css that’s used in EE’s backend.  (I hard coded the css, so it’s going to pull the default style.) The default is not to write the stylesheet.

align - ‘left’ or ‘right’- by default, the calendar is centered via the javascript.  If set, you can override that.

form_id - the id of the form you are inserting the date into.  By default, it will be entryform- suitable for use with the stand alone edit form.  However, it will work with any form you specify.

Then- wherever you want the calendar to show, you put:

{exp:cal_saef:calendar name="entry_date"}
{calendar}
{clear_link} {today_link}
{/exp:cal_saef:calendar}

There is one required parameter- name.  That should be the name of the field where you want the date text inserted when the calendar is clicked.  Once that’s done, you must tweak your form field a bit:

<input type="text" id="entry_date" name="entry_date" value="entry_date" maxlength="23" size="25" class=’input’ onkeyup="update_calendar(’entry_date’, this.value);” />

The bit in bold is the part you’ll need to add.  Make sense?  You need to add the wee bit of javascript so the calendar knows which field to put the date in.