Recording Bass
Recording the Bass Guitar can be a challenge as it containers a large range of notes and overtones. It is very much a full range instrument. The bass can be recorded by putting a mic in front of the bass amp, or by getting a direct signal (DI: Direct Injection or Direct Input) from the bass guitar. Whenever possible, you should try to record both mic'ed and direct signals.
When recording a bass amp with a microphone, common mics are either bass drum mics (AKG D112 or Audix D6), large diaphragm dynamics (Sennheiser MD421), or a large diaphragm condenser (Nuemann U47). A good starting point to record a bass amp is about 12" away. Some prefer closer and some prefer a few feet away. You'll just have to experiment to see what works for the song and production you are working on. If you are placing the mic closer, listen to find the best sounding speaker in the cabinet and aim the mic there.
To record the DI from the bass, you may want to get a special DI box, like the radial Stage Bug or a Tech21 Bass Driver DI. These boxes allow you to send a signal to the board and your amp at the same time. If you are only recording a DI with no amp, you can plug your bass guitar right into the board or preamp for recording. Other options include using an amp simulator like a Line 6 POD. You can plug your bass into this box then run the box's output into your line in for recording.
As always, when using modern digital equipment, record your peaks to about -20 to -10dB. Check the Mixing page for more information on using EQ, compression, etc. when mixing.