" Magical correspondence tables are like a witch's cheat sheet. They list energetic and metaphysical connections between objects, beings or concepts in a neat and precise at-a-glance way.
Correspondence tables allow a witch to quickly throw together a spell or charm based on the correspondences of the items in the table to the intent of her spell. Correspondence tables are a tool to make things easy but should never be considered hard and fast rules. Different practitioners may assign different correspondences based on their own experiences and belief systems. What is symbolic to one person, even if that person is an expert, may not be symbolic to you. Many witches create their own correspondence tables for their personal Book of Shadows. http://www.witchipedia.com/correspondence-tables
Put simply magical correspondences act as tools that augment the energy that the magic user is pushing into any spell or other magical working. Magical correspondences include such things as colors, herbs, days of the week, planetary symbols, Elements, etc. Understanding and using such magical correspondences is central to successful spellwork. So here's some tables that you might find useful.
Herbs/stones : http://www.ladybridget.com/w/corrschart.html
Western Elements: http://www.witchipedia.com/table:elemental-correspondences
Chinese Elements: http://www.whiterosesgarden.com/Grimoire/GRIM_elements/chinese_elemental_correspondence.htm
Days of the Week: http://www.witchipedia.com/table:days-of-the-week
Phases of the Moon: http://paganwiccan.about.com/od/moonphasemagic/tp/PhaseMagic.htm
Planetary Correspondences : http://fullmoon-magick.150m.com/planets.html
Signs of the Zodiac : http://www.witchipedia.com/table:zodiacal-correspondences
Magical Intent: http://www.witchipedia.com/table:correspondence-by-intent
Although spells can certainly be worked without using any of these correspondences, the more correspondences one can include in a magical working the stronger the energies that can be built into a spell. Some Ceremonial Magicians will wait for years for the proper conjunction of the planets while gathering all ofther possible correspondences to insure the most power in their working. So keeping tables like this in your BOS and using them regularly will help to improve your own magical abilities.