I'm trying to create a PHP send send mail form (not for WordPress).

I'm wondering if maybe this should be done in Javascript, too... Advice please!

The form should do the following...

1. Enters recipient's first name.
2. Enters recipient's email address.
3. Select from a variety of checkboxes (attached to attachment files)
4. Select Submit button and either 1) an Outlook email is created with the attachments attached, or 2) the email is sent directly from the server.


Here's the HTML code I've started (I have a lot more to add and this isn't aesthetically the way I want it to look, but it's a start).

Code:
<html>
<body>

<form name="input" action="html_form_action.asp" method="get">
First name: <input type="text" name="FirstName" value=""><br>
Email Address: <input type="text" name="Email" value=""><br><br>
<form>
<input type="checkbox" name="Fin_Form1" value="Fin_Form1">Financial Aid Release Form<br>
<input type="checkbox" name="Fin_Form2" value="Fin_Form2">Financial Aid Application 
</form>
<input type="checkbox" name="Fin_Form3" value="Fin_Form3">Dependent Verification Form 
</form><br> 
<input type="checkbox" name="Fin_Form4" value="Fin_Form4">Independent Verification Form 
</form></br></br></br>

<input type="submit" value="Submit">
</form> 

<p>Please press submit when you're done and your email will be sent.</p>

</body>
</html>
I'm just not sure where to get started with the PHP, which I know will be involved in something like this. I'd like to work on the code myself, but I would like a push (a big push please) in the right direction. If someone could do that, I would greatly appreciate it.