I first experienced grid work when I attended my Reiki Master class. The Reiki instuctor explained how to make a manifestation grid. She used Reiki to "power" the grid. But, any type of energy work will serve the same purpose. Some of my earth based friends use magic, some of my Buddhist friends use mediation and some of my other friends use focus and concentration. The main thing to remember is to give the grid your full attention for at least five minutes every day.
The first thing to do is to write down what it is you are going to bring into your life. Don't use words like want or need or desire. Your subconscious mind is like a giant computer and so is the Universe. All either one of them hears is that you want to want or need to need or desire to desire. So, it brings you more of what you are asking for.
Instead, use words like bring into or choose. Word your intention as if it has already happened, and thank the Universe in advance.
For instance, you could say:
I choose to bring an excellent paying job that I absolutely love into my life at this time. Thank you! Don't try to be too specific. Basically you are giving an open intent and allowing the Universe to fill in the blanks.
Your grid can be as simple or elaborate as you choose. In this case we are going to be using a Major Arcana character card to represent that which we choose to achieve.
Choosing your card is an intuitive process. Spread all the Major Arcana cards out in front of you, and then choose the one that seems to fit your plan the best. You will find that you are drawn to a particular card. Don't second guess yourself. Go with your first intuitive choice.
Now, comes the fun part! You can place stones that correspond to your intent around the Tarot card. Malachite or Jade are good choices for prosperity. Pink Quartz is a good choice for a special relationship, while Jet or Apache Tears are great for standing your ground in difficult situations. Do a little research on the properties of stones and again, use the ones to which you are intuitively drawn.
Asking for assistance from the elemental earth energies is always a good choice. You can place a feather or incense in the east to represent Air. Using a candle or small container of ashes in the south is a good way to represent Fire. A small container of water or some dried seaweed can be placed in the west to represent Water. And, a stone or a small container of soil can adorn the north to represent Earth. Use your imagination. The more interactive your grid--the more focus you can achieve.
Once your grid is built to your satisfaction, it is time for it to be activated. If you use Reiki, simply place your hands above the grid and fill it with Reiki energy. The same applies to magic or meditation. Put your grid in a place you will see it several times a day. You don't need to constantly focus on the grid, but seeing it will remind your subconscious mind of your intent. Send it energy once a day, and allow the Universe to do the rest.
You should see things starting to happen in a week or so. Sometimes, the things are not necessarily what you would expect. But, they are always in the highest good of all involved.
Here is a link to a really great book on the subject of stones by Scott Cunningham.