Here is simple guide to create login page. About design, you can create one as you like using html. This is simple design that i created to demonstrate how login page works. You can use just two text-boxes and submit button, that is all.
Make sure that your text-boxes and submit button are inside the "Form" which uses method field and action field as shown below.
<Form name="Form1" method="post" action="login.php"> ...When you hit login or submit button, all data which are inside this form will be thrown to login.php.
And they won't appear in address bar. Because method is post.