I'm not sure what you mean by "decent one" since all realtors, real estate agents all well educated in their fields, have clean records and all are approved by the state, and that includes the brokers they work for. Yes, you can go to realtor.com and find one in the area where you want to buy a home. Agents usually have an area where they choose to work (like for instance beach front properties, properties over $1 million, some are just buyers agents, some are sellers agents, some like to sell homes in the country, etc. and by looking at the websites of those in the area you want to buy you will know their expertise. Give them a call and see which one you feel comfortable talking with, or ask the broker to refer you to someone.
I had a good laugh at reading all the responses. The questioner asked aboiut a "real estate AGENT" not about Realtors, yet many realtors responded trying to twist the questioner's arma and everyone elses' arms to buy from them or give them a commission just so they could do nothing and yet transfer the prospective client to another agency the individual doesn't know. The competition sure was keen from the responders one trying to say they were better than the other or selling (against the Yahoo Q&A community rules).
Most people suggested a specific broker's office to deal with yet several years ago many, yes many, agencies were purchased by the same company...Yes, you read that right, although they have different names for their agencies most of them are run by the SAME main company, it's just that each office is run by a broker who runs it a tad different than the other one like different advertising, different area, etc.
Yes referrals are good (referral from your family). No, agents for the most part are not paid, they are on commission, and the commission is part of the amount they collect from the seller in the closing costs, HOWEVER a lot of those closing costs go to pay advertising fees, fees for the post and sign and installers, long distance phone calls, etc. etc. that YOU requested be done.
The reason everyone needs an agent (rather than selling or buying a house on their own) is because the agents do all the legwork for you. And the reason you need an attorney as well is to prevent you from getting screwed by the buyer or seller (and not by the agent).
Someone was correct when they said you need to get your own loan first (get one for 30 years) and THEN go see an agent. Not too many agents are doing home showings anymore since there is a security risk. So what you do is call an agent and tell them what you are looking for and have them come to you with their laptop. The reason you meet "outside" of the office is that competitor agents steal clients right from under your nose, and so do brokers. So if you find an agent you like then be ready to hire them to work for you and on a confidential basis. That way they will give you all the time you need, they will bring to you every possible match, and will show you the home or homes, etc., they will give you a printout of the taxes, schools, and anything else you ask for.