I just wanted to stop by and say this is a great idea for a contest. Not only will someone win some great sticks, but a lot of people will be much healthier. Dave has given some really good advice here, especially the information about cardio (HIIT before breakfast is the
only cardio to use for weight loss; I avoid cardio following weights, as it impedes muscle building - the body gets confused about whether it needs to grow or shrink) and building muscle (compound freeweight exercises are your friend - check out
this thread for an awesome and very simple novice weight training workout).
For gaining functional strength, building overall muscle, and improving coordination, isolated exercises (e.g. bicep curls, tricep kickbacks) and especially machines are damn near worthless. They are far too specialized, and are not very effective for the novice weightlifter. Believe me, I know, I spent a long time using them before I started doing my research. Stick to freeweights, and stick to the "main" lifts for the first few weeks. Add in additional exercises
sparingly, and one at a time, after you've gotten used to the workout. And most importantly, your #1 goal with this routine is to add weight every day. If you can't finish your sets, it's OK to leave the weight the same the next time, as long as you get more reps in. But don't add reps beyond the sets. Add weight instead. This keeps your body growing. The more muscle you grow, the more fat you'll lose; even if your overall weight doesn't change very much, your body fat percentage will drop and your lean body mass will rise.
As for nutrition, eat five or six smaller meals per day to keep your metabolism in high gear. In addition to the obvious stuff you want to stick to around two servings of fruit per day, one for breakfast and one immediately following your workout. Fruit's simple sugars are easily converted to fat. For your carbs, eat mostly complex sources (whole grain, oatmeal, rye bread, sweet potatoes/yams, brown rice). Eat lots of veggies - try for five servings per day. They don't have that much in the way of carbs, and they are amazingly good for you.
DO NOT cut fat out from your diet. Your body needs fat. Just change the fat you get. Stick to "good" fats - extra virgin olive oil (you can still fry - or saute, rather - food), fish oil (supplements or eating fatty fish such as salmon), flaxseed oil or flax meal (not whole flax seeds, you can't digest them), one or two egg yolks per day, nuts, one or two servings (of 6-8 oz.) of red meat (90% lean - no fast food burgers).
Figure out the calories you need, and break them down between carbs, protein and fat. Men probably should not drop below 1800 calories per day, and women 1400. Lower than that and your body will think it's starving, your metabolism will plummet, you'll be tired all the time, you'll lose muscle, your immune system will practically shut down, and you'll be damn sorry.
Alternatively, figure out your maintenance level of calories and cut out about 15-20%. For your nutrient balances, you should probably be between 40/40/20 (carbs/protein/fat) and 60/30/10 at the extremes. 50/35/15 is a good all-around balance. One gram of protein or carbs has 4 calories, one gram of fat has 9. Get a sheet of paper and a calculator and figure out how you need to eat. It is much easier to stick to if you write it down. And I know that when you get done you will think the number of fat grams is too high. It's not. You really do need to get that much fat in your diet.
Best of luck to everyone taking part!
Edit: spelling and arithmetic