The first thing you need to know is that there are roadside signs for everything in Walt Disney World. Every area that you want to go to have directional signs for them; every theme park, every water park, every resort, every recreation area and even Downtown Disney are pointed out on signs all over the Disney property. So, if you are leaving your resort to get anywhere that is Disney owned, you just start driving out of the resort, get to the main road and follow the signs.
When you check into Pop, they will ask if you have a vehicle and give you a parking pass that you need to display on your car dash. This is the same piece of paper you will show to the attendants at the park gates to park for free.
When you've been directed to your parking spot at each park's parking lot (you don't have a choice where to park as there will be a CM directing traffic), a good tip is to either write down the area and row you are parked in or take a picture on your cell phone or camera before you get on the tram. There's nothing worse than forgetting which row and area of the parking lot where your car is parked - especially since there will be multiple cars that will look exactly like your car!
There are trams that pick up up at the top of your parking row and then drop you off at the entrance to the parks. When you are ready to leave the park, you will wait for a tram at the designated area and they will drop you off by parking area (another reason you'll want to remember where you've parked).
If you have a reservation at another resort for lunch or dinner, just tell the gate attendant you are there for a lunch/dinner reservation. They may or may not give you a 3 hour parking pass and will tell you where to park. And unfortunately no, you cannot park at any of the monorail resorts and use the monorail to get to Magic Kingdom. You will need to park in the Magic Kingdom parking lot, take the parking tram to the TTC (Transportation and Ticket Center) then you will either need to take the monorail or ferry boat to the Magic Kingdom entrance. Unless you are staying at that particular resort, you risk the chance of being towed (thus the reason for the parking permit you display on your dash).