There's nothing wrong with buying used clubs. Not everyone can afford state of the art clubs from the top manufacturers. You may want to fill in your bag with a few used clubs or you may want only used clubs. Purchasing used clubs will save you money and give you an opportunity to check out a number of different brands.
Go to your local golf course and talk to the manager of the pro shop. Ask about the clubs sold in the pro shop and why they stock them. It's great to learn the rationale behind a recommendation. If the explanation makes sense, ask if they are selling any used clubs of that particular brand. If they are, you may find yourself a bargain. If not, ask if they know where you can get them.
Head to your local golf outlet store. These are huge sporting goods emporia that sell every product a player could possibly need. This includes used golf clubs. They may even have a wide selection. You will have an opportunity to talk with a salesperson. Tell them about the state of your game and what type of shots give you the most trouble. They may have a good recommendation for you.
Go to your local practice range. You will notice that they have a number of clubs that are out a on a rack for use when hitting golf balls at the practice tees. These are not the clubs you want to buy. However, they may keep other slightly used clubs away from the public that they might be willing to sell.
Don't be shy about checking out property or garage sales and even thrift stores. You may not find a complete set to your liking but you may find the driver you always wanted, the lob wedge you heard so much about or even the right putter. Best of all, you might find these clubs at a very good price.
Using internet auction sites can also provide good bargains if you are looking for a particular recommended club. Always make sure and do your research about a specific club before buying it, and be sure the website has a return policy in case you receive damaged goods.