Well, this can be solved in a number of ways. First, you'll need to split your operation into three steps, 1) enter data, 2) preview / edit / approve, 3) store. Say you have a "title" and a "body" field;
file1.php
<input type="text" name="title" size="40">
<br>
<textarea name="body" cols="50" rows="10"></textarea>
// this form submits to file2.php
// optionally an "express" button wich submits directly to file3.php
file2.php
<input type="text" name="title" value="<?echo $title;?>">
<textarea name="body" cols="50" rows="10">
<?echo $body;?>
</textarea>
// this is the edit/approve step, form submits to file3.php
file3.php
// store $title and $body to your database
