Voicemail on asterisk-1.2.7.1 with cisco 7960

Hi

I configured asterisk@home 1.2.7.1 connected with cisco 7960. We have PSTN line and TDM 13B. From the PSTN line we taken two extensions. I can make out calls and extension also. I want to configure voicemail and conference call. How to configure it?

Thanks
SG