Roasts should be cooked in a slow oven so that they don't dry out too much or too fast. About 325 degrees does it. Use a meat thermometer to ensure that you reach the proper temperature for safely cooked meat.

In general, roasts usually cook for about an hour per pound.

•Beef, veal, lamb, steaks, and roast should be cooked to 145 degrees Fahrenheit
•Ground beef, lamb, and veal should be cooked to 160 degrees Fahrenheit
•Turkey, chicken, and duck—whether whole, ground, or in pieces—should reach 165 degrees Fahrenheit
•Eggs should have an internal temperature of 160 degrees Fahrenheit
•Fish should be cooked to 145 degrees Fahrenheit
•Pork should reach 160 degrees Fahrenheit

Here's a turkey roasting timetable.

4 to 8 pounds (breast) 1½ to 3¼ hours
8 to 12 pounds 2¾ to 3 hours
12 to 14 pounds 3 to 3¾ hours
14 to 18 pounds 3¾ to 4¼ hours
18 to 20 pounds 4¼ to 4½ hours
20 to 24 pounds 4½ to 5 hours

Stuffed
4 to 6 pounds (breast) Not usually applicable
6 to 8 pounds (breast) 2½ to 3½ hours
8 to 12 pounds 3 to 3½ hours
12 to 14 pounds 3½ to 4 hours
14 to 18 pounds 4 to 4¼ hours
18 to 20 pounds 4¼ to 4¾ hours
20 to 24 pounds 4¾ to 5¼ hours