Just keep top dressing with shredded leaves, compost, grass clippings, wood chips, etc., and the worms will do all of the amending for you.

Water regularly indicates a plant that can probably not tolerate being on the dry side. Plants vary a great deal in their water needs. How often that means depends entirely upon your soil and your site. You'll have to learn by experience how long your soil hangs on to moisture. Watch your plants and dig around in the soil with your fingers.

Having said that, a brand new garden will need to be watered more frequently until the plants are established. That won't take too long.