Here's what I've read on this board:

Cardio- Cardio burns fat best on an empty stomach. It is best to do cardio first thing in the morning. If you do cardio later in the day, do not eat for two hours before and one hour after.

Weights- You need fuel to get the energy to lift weights. Eat a carby snack 45 minutes before your workout for this energy. Try to then eat immediately after your weight training, within 45 minutes. It's best to ingest a great deal of protein to send to the muscles. Some carbs are also good at this time. Avoid fat, as it will interfere with the deliverance of the other nutrients. I drink an Isopure shake (40g protein, 0g carb, 0g fat) and eat half an apple (8g carb).

Hope that helps and that that info is correct.