The obvious place for a dishwasher is right next to the kitchen sink. Dishes and pots can be scraped and rinsed, then placed in the dishwasher without moving your feet at all. Another logical location for a dishwasher is near storage areas for dinnerware and pots. In larger kitchens, a second washer is sometimes placed in a center island or near food prep areas.
Quality appliance manufacturers place little or no limitation on how far away from a sink you can install their dishwashers. The unit will include standard, flexible supply lines and a drainage hose that are about 6 feet long. If you need longer pipes or hoses, you can usually get them at home centers. You'll need to consider where the lines will have to travel to get to the sink cabinet. They may need to snake behind or under other cabinets. Your unit's owner's manual will specify any limitations regarding appliance location and distance.
If space is your issue with dishwasher location, consider a smaller unit. Quality, compact, 18-inch-wide dishwashers clean dishes just as well as their full-sized 24-inch cousins. Dish drawers -- dishwasher units that pull out in two sections like drawers -- don't have to be installed one on top of the other. They can be installed in two separate and convenient areas. You can also install just a single dish drawer if your space and dishwashing needs are minimal.
You get what you pay for when it comes to dishwashers, so buy the best you can afford. Quality dishwashers have stainless steel liners and enough power to knock dried egg and crispy lasagna noodles off pots and pans in one run. Choose a dishwasher that allows an economical quick wash for dishes and glasses, as well as an extra-long wash for crusty pots and pans. If you get a dish drawer, you can load one drawer with dishes and the other with pots and pans so they can be run on different settings.