Why is it that some people find the idea of contacting a new plumber to do a job, just a little bit worrying? There have being a spate of documentaries on the TV and stories in the media about "Cowboy" plumbers, sad tales of people losing their money. Yes, there are rogues out there but in truth they are few and far between.
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.
Some faucet replace valves do not take washers and therefore you cannot repair them. If you have a washerless shut-off valve that leaks it will need to be replaced. You will need: a propane torch, solder, flux, sandcloth, a wire fitting brush, a small section of copper pipe (most likely 3/4" I.D.), a slip coupling (again probably 3/4") and a shut-off valve. I would highly recommend installing a ball valve with a drain on it as opposed to a washer style valve. If you purchase a decent quality ball valve it will last a very long time.
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.
If you have to call your Local plumber to do work such as renovating your kitchen or bathroom, purchase the parts yourself directly from your plumbing merchant. You can often save considerable money by buying this way, and most plumbers are happy to supply you with the information to enable to buy the correct fixtures for your job.
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.
Once the work has been completed, ask for a breakdown of the bill before it's paid. That way, you know what you're paying for and it stops the plumbers asking for more money down the line.