Basic Home Network questions

I thought it would be cool to set up an iCal server and Address book server so my family can stay more organized.

I bought Lion Server, but it's not as straight forward as I had hoped.

1) Does it matter if I use the .local or .private extension for the host name? Eventually I'd like to set this up for VPN use.

2) No matter what I do, I cannot get iPads/iPhones to access the iCal/Address book servers. I have been using NAME.local or NAME.private, depending on my configuration.

Thanks!