How to migrate my Mac OS X application and data from MacBook Pro to Mac Mini?
As @Globalnomad says using the Migration Assistant is the easiest way as per the Apple reference . However you do not need the extra disk but connect them with a firewire cable see Apple knowledge base for firewire booting
The steps are given in the first reference in he section "Migrating using FireWire or ThunderBolt "

or if no Firewire cable - connect via Ethernet and use the section "Wireless (Wi-Fi) or Ethernet migration"  I suspect Wi-Fi might be a bit slow.