Ask around. Ask your friends, ask your neighbors and get referrals. Nothing is more powerful than the testament of someone who has had a local plumber in their home and can speak to his/her capabilities.
As a Plumber you have done your time and got your trade certificate. It wasn't given to you because you had to earn it. You now have the right to make a fair and honest living from it despite the down turn in the economic climate.
Second, do you have the knowledge required to solve leaking pipes/faucets and clogged drain problems? You should be able to understand the parts of the faucet, pipes, and drain. Various types of faucets are sometimes designed to function very differently. You should know how to dissemble it replace the busted part and bathtub replace put it back together again. If the problem is in the pipes, you should know which one you have to remove and replace.
A Trustworthy plumber will answer all of your questions. Good plumbers will provide you with references, and tell you how long they have been a plumber, and the type of guarantee they provide for their work (warranty.) As well, a professional plumber will offer emergency service for nights and weekends. You should be able to make contact with him or her in a timely manner. A professional plumber will also have all of the appropriate insurance such as liability insurance so that you are protected in the event of an accident.
Call a Local plumber to set up an appointment for an inspection. You will need to be home for this service and when the work is complete, you want to be available to find out what the professional found out. If there is work to be done, depending on the severity, it might be a good idea to go ahead and schedule the next appointment for repairs.
Before choosing any plumbers in your area be sure you pick a contractor that has experience with similar projects as yours. Plumbing in your area isn't the same as say New York or Chicago, unless of course you are from one of these cities. Ask for a reference or two for plumbing jobs that they have completed in the past.
Most importantly, make sure that you set your foot in a reliable and trustworthy store which also offers great discounts or sales for you to be able to save.