Check your drain and filter, it may be stopped up with food particles. That's just one of the reasons I make sure I wipe my dishes off before putting them in the dishwasher.
Sounds like something is blocked or clogged. What you can do is call the company who made your dishwasher and have the make and model numbers ready. They all have a technical support line and can best advise you.
There is always some sitting water in the bottom, it just depends on how much.. You can remove your plastic covers on the bottom and make sure there isn't anything clogging up the screen to the pump..
WE had that very same problem. It's the pump that sucks the water out. Check your drain at the bottom to see if anything's blocking it (like washed off labels, big chunks of foodies, etc). If there's nothing there, check your drain hose that hooks up to the faucet. Maybe there's something there clogging the outflow to stunt the pump from working right. If all else fails, replace the pump. There's google videos on ""how-to"" & you could do it yourself or just hire a plumber (some will, some won't) or repairman/woman. Quick fix if properly done.