I am in the process of selling my home. I need to know if a buyer needs to have an amount of money put in the contract as a "down payment" to the seller. You know in case the sale doesn't go through then the seller gets that money.

Yes, there should be some kind of earnest money deposit to cover the seller in the event the buyer defaults. A common amount is 5 to 10% of the purchase price.

If you are selling your home without a realtor then I strongly recommend that you get yourself a real estate attorney to handle this for you. They will prepare and negotiate the contract as well as handling the closing for you. It should not be expensive (approx. $500 to $1500 depending on your location) and you will know that someone is looking out for your interests.