for the herbs and oils, go with Scott Cunningham's Incense Oils and Brews, as well as his book Magickal Herbs or Encyclopedia of Magickal Herbs. in regards to your spirit guide, meditation is usually best. i don't know of any books on the subject, but it would probably be in a book about shamanism.
that might be of some help. read about the creature and see if you feel connected to it, then meditate thinking about the animal, or asking yourself who your guide is. normally you will see/hear/feel something. it will most likely take a few tries though.