First Determine Your Gold
The first thing you need to do when selling gold is to determine what type of gold you are trying to sell. Is it gold bullion or scrap gold? Gold bullion is definitely the more valuable of the two and is pure gold often issued by governments in exchange for currency. Scrap gold is gold that is made into jewelry, dental gold or electronic materials. Identifying this first will lead you to the right buyers of this gold, as scrap gold buyers won't give you the right prices for gold bullion and gold bullion buyers won't buy scrap gold from you in the first place.
Selling gold bullion isn't terribly difficult, though finding a gold bullion dealer may be a bit tougher. Once you find one who has a good record and you think you can trust, you need to bring them your bullion and they will give you the market price for it. In most cases, whatever price has been set for gold by the market is what gold bullion will sell for to a dealer: there is no haggling. Check out a resource like Kitco to find the stated price of gold or watch this price over the course of a month and see how it fluctuates. If it is going up consistently, then you might have a chance at selling your bullion for a higher price than the market is asking. Of course, this primarily depends on how much bullion you are selling in the first place. As most bullion is almost entirely pure, you only have to multiply the price you are asking by the weight.
Despite the name, you can still make a lot of money off of scrap gold, as there are many pieces of jewelry out there which are made from pieces of gold that are almost entirely pure. However, finding a dealer who you can trust to give you the accurate price is tougher, as there are tons of scammers (usually anyone with an online ad that runs late at night) who are trying to give you a fraction of the price for your gold pieces. Check ratings of these gold dealers online and read reviews about their cash payouts, customer service, turnaround times and shipping insurance. If there is anything that is regularly negative, don't send your scrap gold to them and find someone else.