Don't expose your bass to extreme temperatures, excessive dryness or humidity, because these all can harm your wooden instrument. The optimum storage condition is relative low humidity, with a temperature around 70 degrees. Keep it in its case when you're not using it.
For gig travel, transport the bass in a hard shell case to protect it. Loosen the tuning knobs a bit to take pressure off the neck before taking off for the show.
The dust, dirt and sweat of the night club scene exposes your bass to some less-than-clean conditions. During play, it's a good idea to have a sweat cloth nearby to wipe away perspiration. After each gig, take a few moments to wipe down the instrument with a chamois cloth. Go over the body, neck, headstock, fingerboards, tuners, pickups and bridge. The strings need particular attention, as they can rust.
Maintain your bass at home by keeping the wood polished. Use a clean dry cloth and guitar polish. Do not use products designed for furniture, and never use an abrasive. Use a dry cloth on the pickups, but because they can accumulate a lot of dust, you may need to use cotton swabs to thoroughly clean them. For the hardware (bridge, strap pins, tuning heads), clean with a dry cloth. For the fingerboard, remove the strings and use a drop or two of lemon oil or fingerboard oil applied with a clean cloth. Be sure to remove excess oils. You can clean the frets with a mild jewelry cleaner.
Clean the strings individually with a guitar string cleaner. Change your strings regularly--how frequently depends on how often you play. If you're playing daily, you can expect to change your strings a couple of times a month. Replace one string at a time to avoid undue tension release and resulting stress on the bass neck and bridge. Be careful when removing strings so that you do not scratch your instrument.