We use drip hoses to water the garden because by watering the roots and not the foliage you lose less water thru evaporation and help to prevent fungi based diseases, which can happen when you water from the top. In our area water is rather expensive, so every drop we can save saves us money. We use the basic porous drip hoses, made from recycled tires, available in most hardware stores, Sears, garden shops, etc.
We cover the drip hoses with 3 mil black plastic, which comes in rows 10x25. Since our garden is about 10 wide and 40 long, we need two of these plastic rolls, which is very inexpensive. The plastic lasts the entire season and its main purpose is to prevent weeds from appearing and retaining the moisture from the drip hoses. This is why we spend no more than 5 minutes per day weeding our vegetable garden and why we dont have to water too often. Using black plastic is economical, practical and efficient.
After you turn over the garden in spring, you must dig the trenches that hold the drip hoses. We use a V shaped garden trowel for this and simply lay the three hoses lengthwise down the garden. Since our garden slopes to the west, we keep the trenches towards the uppermost part of the garden, and allow gravity to soak the lower part, which seems to work fine.
When we first used drip hoses we ran them up and down the garden widthwise, rather than lengthwise. This turned out to provide us to TOO MUCH water and we went to a lengthwise layout.