Do not toss that broken appliance until you have had a closer look at it. Small appliances sometimes need nothing more than thorough cleaning and lubricating of the working parts. Electronic appliances, such as your microwave, dishwasher, washer and dryer, and refrigerator may only need a replacement electronic panel --- which is a snap-in part. You can use regular tools to repair most household appliances.
Retrieve the paperwork and booklet that were with the appliance when you bought it. Many manufacturers place a troubleshooting chapter, sometimes with schematics, for the do-it-yourself repairperson. Read the information to see if anything applies to your problem.
If you do not have the original handbook, then go to the manufacturer's website to download the repair manual. Have your make and model number handy. Some companies do not have the manual posted online but you can still download it. Do a Google search for "free appliance repair manuals" and look for yours. You may have to visit a few websites until you find the one you need but just about everything is available online.
As you read the manual, keep referring to the schematics if you have not worked with them before. If you are still having a problem understanding something, then post your question in an appliance repair forum. Start with the website where you downloaded the repair manual. The forums are filled with friendly and helpful people who are willing to help a beginner.
Before working on the appliance, find out if you need to follow any special safety precautions. For example, what do you need to do if you are trying to repair an appliance that may have CFC's or a high-voltage part? Put safety before savings --- a repair bill is cheaper than a medical bill.
If you find that you enjoy repairing small appliances, then register for a class at your local night school or community college. Call your local school board to request a night school schedule. Another option would be to take a home study course. However, the friendships and benefits of hands-on practice in a classroom might be worth the extra effort to go to class until 10 pm.
So, the next time that you want to toss that $400 dishwasher or $250 stand mixer, see if there is some way to repair it. If you decide that you still would rather replace the appliance, then inquire about donating it to a school that teaches repair. They are happy to take your rejects for the students to evaluate and repair. This is, after all, the green choice --- recycling instead of tossing.