I heard that exercising in the morning can be bad for you, can't remember why.
There are guidelines on calorie intake but everyone burns them at different rates. The basic rule is to take in less than you actually burn. I don't count the calories, just try to eat sensibly and have a balanced diet although I don't always succeed.
The latest fad is the Atkins diet where you cut out all forms of carbohydrate. If this is too hard for you to do then cutting back on carbs should help (pasta, bread, rice) to lose weight.
Exercise is only useful if it increases the heart rate so 20 minutes leisurely exercise won't have as much benefit as 20 minutes hard exercise, although it is better than none.
I train 3 times a week for about 1.5 hours a time. Others do 30 minutes a day, every day. Of all the exercises you do, only the 10 minute run will have any great effect on burning calories as it is aerobic. The key is to do it regularly and increase the times as you go along, the more you do the more you burn off.
Don't expect miracles overnight but stick at it and you will achieve your goal.
As for the lager, it works for me.