Pass form input via url variable

The first form:

<form method="post" action="some-url.php">
    <input type="email" placeholder="Email address" value="" name="email">
    <input type="submit" value="Submit" name="email-submit">
</form>

Then in some-url.php:

if( isset($_POST['email'] )
    $email = $_POST['email']

The post method would be preferred here since it won’t create server log entries that include the user’s email address.

You should also do this over SSL since you are collecting “name, age, etc.”