Make sure you new computer has the power to record. Do some research on minimum system requirements for recording, especially processor speed, RAM, storage space, ports, card slots, etc. These requirements will depend somewhat on the number of tracks you plan to record and the number of plugins (software-based effects) you will use on each track. You also need do decide how your music will enter the computer. This means choosing a soundcard with a breakout cable or an external interface (USB or Firewire). And you will need a multitrack software recording application like Cubase, ProTools, DigitalPerformer, Logic, etc. There are a bunch of possibilites in this area and your choice will depend partially on what platform you choose (Mac or PC), what you budget looks like (applications can run anywhere from free to 1k), and whether or not you will integrate MIDI into your music.