Honestly, for a basic set up I've never felt the need for anything more than a screwdriver and some allan keys, and I like my action very low. Try reading through some of the guides online (like the Willis or Jerzy Drozd ones), apply it to your bass(es). If you're happy, sorted. If not, you can buy additional tools and resources.
It's not voodoo, but the only way to learn is to try it IMO. It's pretty difficult to do any permanent damage unless you're using totally excessive force.