I am overweight, I'm 5Ɗ and about 175 pound, I might be less. . .I just would like to know what is the quickiest and most healthiest way to lose weight. My goal is to lose 21 pounds or more by my 21st b-day which is in Dec. Also what is good weight for someone my height? Cause I would like to lose about 55 pounds or 60 pounds, if that is normal and healthy.

For men 132 - 138
for women 114 - 127
Follow diet restrictions by avoiding junk food and food containing fat and do exercises regularly.

Hi, first and foremost, Congratulations for wanting to do something with respect to your weight. I have struggled with weight problems myself and I have come to "learn" a lot of diets and gimmics that just don't work and once in a while one or two that do. Out of everything i've seen, i think the best thing you can do for yourself, especially at your age is to check out a weight loss camp. They're not just for morbidly obese people. I go all the time, whenever I feel i could stand to lose 15 or 20 pounds and I find it to be very refreshing and very healthy. They CAN get pretty expensive, but boy are they worth it. After i go, I eat healthier, do more exercise from all the nutrition and exercises i get back in touch with. Check out a site called fitnesscamps.net, they list a couple of sites, but better than that they respond to a bunch of questions from far more qualified people. Thanks to the site I've learned about a couple of new places that i have really come to like now.

Drink lots and lots of water everyday.

we have the same bday!
anyway...as much as it sucks, there is no quick and easy way. when i was younger, i was at 150, and through exercise. and eating healthier (not dieting), I went down to 120. I've been maintaining it since...but I do exercise, and watch what I eat.
your goal should be to lose no more than 2lb/weeks...otherwise you will gain it right back..so take it slow and steady, and you will thank yourself later.
also, this requires committing yourself to changing your habits and lifestyle, and not a one time thing...or you will be yo-yo-ing like crazy.
good luck :)