What precisely do you need to know? If you have a background of music and are classically trained/can read music etc it should be pretty easy to pick up once you get a feel for the instrument, especially if you played double bass! It's pretty much the same core concept... I played piano and was able to migrate to electric bass pretty easily once I got a feel for the instrument
Once you have the basics down it's pretty easy to transfer all of that musical knowledge you have!