Im New In Exchange Server

Hi to all,

im am new to exchange server, i to install a exchange server 2007 at my home for studying purpose. i install it properly, i can send and recieve email locally but not in outside from internet. i have internet connection at home is a broadband connection and i register my domain name to http://www.hosting24.com.

can some guide me, what more should i need to or what are the requirements setting so that i can send and recieve email from the internet. should i need a public ip address or can i use my internet connection only without public ip address.

pls kindly help me, thank in advance..