I was looking to buy a Convection Oven and wanted to know if there are any general differences in baking methods between the two.
The forced movement (convection) of the hot air by fans is what improves the cooking in a convection oven. The beautiful part is that it allows you to cook on ANY or EVERY single rack in your oven. Here are the adjustments you'll need to make:
For baked goods you typically drop the temperature by 25°F (10°C). If the recipe says to bake at 350°F then you'd bake at 325°F in a convection oven. This is most important in baked goods so that the interior has a chance to cook through before the exterior is overcooked or burnt.
You also need to decrease the baking time by 10-15 PERCENT. To make it easier to determine when to check, I usually suggest checking the item about 5-10 minutes earlier than the shorter time indicated in the recipe. If a recipe says bake 25-30 minutes, then check it at about 20 minutes. It may need a bit more time but you'll be pretty close.
When roasting meats and vegetables you can use the above method OR you can leave it at the regular temperature and then cook for 25-30 PERCENT less time.
In the instance of method #1 for meat you'll get less shrinkage and less chance of possibly drying it out.
In the instance of method #2 for meat, it will cook quicker and get better browning and therefore a bit more flavor.
A third option to take advantage of both methods is to cook it at the reduced temperature for most of the time but then turn it up 25-50°F for the last 20-30 minutes of cooking to improve the browning.
Because of the improved heat transfer, you typically need to decrease both the time and temperature when converting from conventional to convection ovens.
Some convection ovens will do the conversion for you -- you enter the time & temp for the recipe, and it'll adjust it to the time and temp for convection cooking.