You can do it in 2-3 months if you're dedicated.
Check out:
http://johnstonefitness.com/html/training.html
And get your nutrition right. If you're lifting you want 40% protein, 40% carbs, 20% fat. That depends though, play with the ratios to see what works. Here's how I eat:
Breakfast:
Optimum nutrition chocolate protein drink. 43g with skim milk.
1 cup of crispix cereal
snack 1:
3/4 cup cottage cheese
2 pieces of turkey
Lunch:
Turkey breast on wheat bread. Tomato's, lettuce, mustard.
Piece of fruit.
Snack 2:
ON chocolate shake. 21g w/ skim milk.
Natural (yes, natural. avoid sugary fake peanut butter) peanut butter on a piece of celery.
Post workout snack:
ON shake. 21g skim milk.
Bannana or cup of oatmeal.
Dinner:
Boneless chicken breast.
Sweet potato/Baked Potato/Potato Salad/Potato Soup (carbs. good ones).
Vegetable (I like sweet peas).
It's all calories. Burn more than you eat. If you eat 10 times your body weight in calories then you'll be eating just enough to lose 1-2 lbs a week.