Yes, how depends on whether you're talking about an authoritative DNS server to host DNS for your domains (in which case, use the dns-server package), or whether you just want something to use as the DNS server on your internal hosts. In the latter case, the built in caching DNS forwarder is great for that.
yes. there is a dns-server package, which is a tinyDNS port. Haven't used it myself, so YMMV.
Yes, how depends on whether you're talking about an authoritative DNS server to host DNS for your domains (in which case, use the dns-server package), or whether you just want something to use as the DNS server on your internal hosts. In the latter case, the built in caching DNS forwarder is great for that.