DSL Exchange 2000 Domain Setup

When setting up Exchange Server 2000 in it own domain with an ISP DSL connection (static IP address)provider does the limit of email accounts which is “10” on the ISP(Service Provider) side affect the number of externally accessable email accounts available in Exchange? As I have never set up a domain with this kind of setup before. Where would be a good reference for an overview of the installation process for this kind of installation?