Referrals are always a good way to go. Perhaps a friend, co-worker, or family member recently bought a house in the same community and had a good experience. You want an agent who knows the area in detail and has already previewed many of the homes available for sale in that community. Community knowledge should be important to you because you are not just buying a house. You are buying a home in a local neighborhood in a specific community.
Every Realtor can show you all the properties available for sale in the Multiple Listing Service. Since that is true, you can call any real estate office and find a Realtor willing to show you houses for sale. The problem is that you do not know if you are talking to an excellent Realtor or an inexperienced, inactive one.
The web is a good place to start looking for the agent who's right for you. There are lots of directories that list agents, plus search engines, too. Peruse the sites. If an agent has lots of information on their site and seems genuinely concerned about informing homebuyers, that's probably a better choice than someone whose web site only talks about how good they are.
The client should be the focus, not the agent. Also, speak to professionals from real estate related professions and ask their opinion. If you know someone who is employed as an escrow officer, title representative, homeowner’s insurance salesman, or loan officer, they will be able to recommend Realtors from the area they work in.