An auto-drip coffee maker is handy, you don't need control the temperature or the water ratio as it pours over the beans automatically. The key to good auto-drip is to keep it as basic as possible, starting with the right coffee beans and roast.
Since you can't control a lot of the variables that make a cup of coffee good with an auto-drip it's important that you start the process right. This means fresh-roasted whole beans, getting a good grinder, fresh water, and trying to get the temperature as close to right as possible.
For most auto drip coffee makers you want a medium fine or fine (remember, never uses very fine espresso ground to auto drip coffee makers) grind depending on the type of filter your coffee maker uses. Here's an estimation of how fine to grind it:
It might take a little experimenting to get the right grind. If your coffee is too bitter, try a coarser grind. If it's lacking flavor, try a finer grind.
Most auto-drip coffee makers are also programmable, and set it to automatically wake you up in the morning. It's best to start the coffee brewing immediately after grinding the beans to capture all the flavor.
Since a cup of coffee is mostly water, the quality of that water is important. If you live in an area where tap water isn't very good then use filtered water for your coffee. You might think the taste of coffee can overwhelm the taste of bad water, but it doesn't.
Additionally you need to play around and get your water to coffee ratio right. In general, you want about 1 or 2 tablespoons of ground coffee per six ounces of water. Your preferences may vary, so feel free to try different amounts. Once you get a good ratio, stick with it. When you're doing so, run a few tests on the "cup lines" on your brewer to see how they actually stack up. Different brewers gauge the cups differently and it might not be six ounces.
The set it and forget ease of a drip coffee maker is great, but one of the side effects is that it can be hard to remember to keep up with the cleaning and maintenance. If you're making coffee every day it's important to clean and spray out the carafe daily because otherwise you're just getting a second taste of yesterday's brew. You should also clean out the whole system at least once a month, some of the auto drip coffee makers, like Melitta® Aroma Enhance™, did include descaling program to help you clean the system easily.