The plumbing courses cover all the aspects that you will be required to deal with as a garbage disposal. You will be taught about the basic aspects as well as about health and safety issues and sanitation.
When you get to the house stand if front of the toilet and locate the water shut off valve. Should be down below the toilet on the wall. Just turn it off (righty-tighty) completely and flush the toilet. All the water should have left the tank, well at least most of it. If there is remaining water line repair get it out with paper towels or a rag. The important thing is that no more water came in. If it did then your valve is not shut all the way or not working and you need additional help.
After you have the stems out you should be able to find the washer on the "inside" end. If it is nicked, torn or brittle it is likely the cause of your drip. Even if it looks brand new, go ahead and replace it. You've already come this far. You can get replacement washers at almost any hardware store. Sometimes you may want to replace the whole stem, especially if the handle end is stripped out. It's best to just take the stem with you to the store and see if you can match it up. Most Do It Yourself stores have replacement stems for many popular brands. If your valve has a center diverter valve to switch the waterfrom the tub spout to the shower head the same process applies. Many times it is easier to replace the diverter stem than to repair it. This really depends on the design of the stem.
The next step in this process is to determine what type of method is available for fixing the problem. You cannot just caulk a crack or fill it in with cement and hope for the best. Unfortunately, there is more work than this because you have to fix the problem from both the inside out and the outside in. This takes a professional in most cases to determine the best method for repair.
Remove the cap of the faucet using slip-joint pliers. Tape the teeth of the pliers to prevent damage of the surface. Remove the faucet cam washer and water line repair the rotating ball.
I bought a new kitchen sink from a brand name building supply company and hired a plumber to install it. After he had left and I filled up my new sink to wash my first load of dishes in it, I noticed the water level had dropped. You wouldn't want to feel my shock and imagine the angry words that came out of my mouth! I couldn't believe that I had spent $300.00 on a brand new sink that couldn't hold water!
Find out if the plumber works on a 24 hour basis and, if so, what are the extra charges involved. More important than the costs however are the person's trustworthiness and reputation. After all, he or she will be in your home and around your possessions. You should feel comfortable with their presence and confident that they are honest.