Cry a lot, then take it to a computer shop for evaluation. Even if it looks like it might run now, there may be internal damage (water into the HDD), which will fail in short order.
What should you do? - Start saving for a new laptop
You could Remove the battery and leave it in an airing cupboard - I would give it at least a week, however most likely the laptop is toast. Simply drying out the water (however long) isn't normally enough. Even in the small time it took to shut off the laptop remove the charger and the battery, the water will have caused a electrolytic reaction, damage and corrosion on the motherboard.
This will remain even when the laptop is dried. To stand any chance of saving the laptop you need to get it to a workshop capable of motherboard level repairs and ultrasonic cleaning facilities. Unless it is a MacBook this would make it uneconomic to repair as usually a new motherboard is needed
Turn it off. Put it in the warm airing cupboard for 4 days,bin a paper bag with lots of uncooked rice to draw the moisture out.
Only turn it on after 4 days minimum!
turn it upside down, then put it a tupperware container or better, Dri-Z-Air is my first thought. also: Q-tips between the keys at the keyboard?
The best thing you could ever do is turn off the computer immediately and bring it to a technician. Water can fry your computer because of the sediments in water, unless you drink distilled water. However, because your PC got wet does not mean you did not damage it,but its best it gets checked before you plug it up.
I spilled water in my xbox 360 (is pretty much the same as a PC) twice and it works still. If you have technician skills, take your computer apart and clean with alcohol. Because they both a computers, they both have a motherboard and many parts shared like a computer. Odds are however your computer can be fryied is like squared the time it is on afterwards before you unplug it.
The best thing you could ever do is turn off the computer immediately and bring it to a technician. Q-tips between the keys at the keyboard. The rice thing didn't work for my cell phone.
There are foams that you can get help absorb the moisture from your laptop. I'm not sure if you can get them at Walmart but you can get them online at websites that sell products for computers.
Do not power on the laptop take out the battery and you should remove the keyboard If you need Help on how to remove the keyboard contact me,after removing the keyboard take a look if any water passed the keyboard,and depending on the brand it may not be able to get to the motherboard