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.
If there isn't' anyone you trust who knows a good plumber, check websites that will you show a list of available plumbing experts in your area. You'll find that there are so many web directories that you can use and you just have to know how to utilize these sites efficiently.
How do you determine if it is an emergency? Look at the source of the problem. If water is not moving and the sink is just full of water that isn't draining, you haven't found a real emergency. If the faucet in the sink will not stop running, and the water isn't draining, it may turn quickly into an emergency service.
If you still are not lucky in finding a good local plumber, contact your local plumbing store, they can help you in recommending a reliable and Trustworthy plumber in your area as they deal with them every day.
Your septic tank has to be emptied sometimes, and there's no easy answer to when it should be done. It depends on the size of the tank and the (sorry to mention it) consistency of the stuff going into it. Basically, if the septic tank isn't pumped out regularly, it will cause you thousands of dollars worth of problems. Ask your Local plumber for advice on your septic tank maintenance.
Shower and Tub Problems: One of the common problems that arise at every home is that the shower head gets clogged with minerals from water. When your tank is not cleaned properly, the water waste gets clogged and you do not get water flow. In this case, you need to remove the shower head and clean properly. Also, drains get clogged often with hair, dirt and other wastes. Water flows towards your feet when you shower. You need to check out and clean the drains.
Hourly fees are another thing you want to check out before you hire a plumber. Call around and get a few estimates for a job. Ascertain if the plumber is willing to sign a quote and give you a price warranty before he begins working. You should also find out if the plumber will require you travel time to and from your job and how they will compute that time and prove it to you. Giving you a precise price may be challenging, but any plumber who can't give you a comprehensive explanation of how you will be billed with an estimate of the cost should be avoided.