By far the most important preparation for living in an area subject to earthquakes is to look carefully at the buildings you will occupy. The best kit in the world won't do you a bit of good if you are killed when the building collapses on top of you! Select structures that were built to modern earthquake codes. Failing that, look into a seismic retrofit of an existing structure. Living/working in an earthquake resistant structure is absolutely the most important first line of defense in earthquake country!

By the same token, try to avoid locations subject to tsunami innundation. If you must locate in an area that might be flooded by a tsunami, plan and practice your evacuation route to high ground.

Beyond that, for the most part the same principles apply as for any major disaster. You want to be self sufficient for at least one week (several weeks is better) with food, water, first aid supplies, necessary medications, etc. Even after initial help reaches you, expect that transporation routes, power, natural gas, etc may be disruped for months.

A few additions to your kit specific for earthquakes might be in order. Expect that some structures will collapse, and people will need to be rescued. A powerfull hydralic jack would be a valuable tool, as would cribbing material, axes, saws, etc. Fire fighting gear might also come in handy. While your building may not fall down on you, it might be so badly damaged as to be uninhabitable after a quake. Tarps and tents to rig a shelter could be valuable.

Edit: Also find out about emergency plans for the larger community around you. Learn what outside resources might be available, and how to access them. Get involved with community volunteer groups (CERT, Red Cross, volunteer Fire Dept, volunteer SAR, etc). You will learn a lot that will help you, and be better able to help those around you.