You don't need a huge garden to reap the benefits of companion planting.  Start simple with a windowsill herb garden:

• Fresh herbs will make your cooking delicious
• Plants in your home will create a higher indoor air quality
• Save money: store-bought herbs are expensive
• Create less trash: no packaging to throw away

Get really simple by buying a Garden-in-a-Bag .  Just open and water. 

Penn State has put together this fantastic Searchable Database for every herb.   Included in each result is information about companion planting.

Garden Guides has published an extensive list of herb resources. 

Here's an article that takes you step-by-step through starting a kitchen herb garden.

Herb Companion is a magazine for the avocational herb gardener. 

The Herb Society of America 

National Gardening Association