I have recently started using aromatherapy oils for stress, anxiety, depression and insomnia
This site has excellant advice about oils.
www.holisticonline.com
Essential Oils For Stress-Related Problems
Anger, Anxiety: Basil, bergamot, chamomile, clary sage, cypress, frankincense, geranium, hyssop, jasmine, juniper, lavender, marjoram, melissa, neroli, ylang-ylang
Depression: Basil, clary sage, grapefruit, jasmine, lavender, melissa, neroli, rose, sandalwood, vetiver, ylang-ylang
Insomnia: Basil, chamomile, lavender, mandarin, marjoram, melissa, neroli, petitgrain, rose, sandalwood, thyme, ylang-ylang
Nervous Exhaustion: Basil, cinnamon, citronella, coriander, ginger, grapefruit, hyssop, jasmine, lavender, lemon grass, peppermint, nutmeg, rosemary, ylang-ylang
Nervous Tension: Basil, bergamot, cedarwood, chamomile, cinnamon, frankincense, geranium, jasmine, lavender, marjoram, melissa, neroli, palmarosa, rosemary, vetiver, ylang-ylang
http://www.holisticonline.com/stress/stress_aromatherapy.html
I buy my oils from here www.oils4life.co.uk, some are expensive so have a browse around different shops and sites.
If you're using the oils on your skin you will need a carrier oil and you add usually around 5 drops per Essencial oils per 10ml of carrier oil.
Hope this helps.