If you are making 25 cups of coffee, and the cup size is about 6 ounces, then you need about seven and ¾ scoops of coffee.  For my drip coffee maker,  I put in three scoops for every ten cups of coffee that I want to brew.  It tastes great because I keep the glass carafe clean, and the water is cold at the start of the cycle.   If you grind your own fresh beans, it tastes even better.  I have been buying Dunkin Donuts coffee beans and they cost a lot less then other beanery brands, but taste fantastic.  Use the scoop that came with your coffee maker, and remember not to let the coffee sit for too long, on the warm plate.  If it sits longer then 25 minutes, it is not going to taste good.