It should be noted that, as wonderful as they are, all kinds of mint and oregano are highly invasive, and will take over any garden space if not kept firmly in check. They are better suited to individual containers if you are not a highly vigilant weeder. There are also companion issues amongst herbs, i.e. sage and chives don't get along, basil doesn't like thyme... A good resource can be found in wikipedia, a list of companion plants - herbs.
It should be noted that, as wonderful as they are, all kinds of mint and oregano are highly invasive, and will take over any garden space if not kept firmly in check. They are better suited to individual containers if you are not a highly vigilant weeder. There are also companion issues amongst herbs, i.e. sage and chives don't get along, basil doesn't like thyme... A good resource can be found in wikipedia, a list of companion plants - herbs.