Is it the Australian site you've joined? There's a calorieking.com.au site and a calorieking.com site. I've no idea of how the American site works, but hopefully people here can help you with the Australian site.
Did you start with your personalised diet and fitness program? If you click on 'Account Settings' at the top of the page you'll find a category of Personal and Community Settings. The first link is taking a personal profile. This will give you your recommended calorie intake per day and how much exercise you should be doing.
If you click on 'Today' (again at the top of the page) you have a heap of options. You can record your food for the day or record your exercise. You can check in to record your weight if it's your weigh-in day, or look at your progress if it isn't. You can also check out the Calorie King University which has a 13 week course in weight loss. You also have a link there to check out the forum or start your own blog. This is the page you should be sent to whenever you log in so it's not hard to find.
I find one of the most useful things about Calorie King is the food recording. Because it's Australian it has lots of the food you would eat every day in its database with the calorie/kilojoule content, how much fat it has per serving, protein, fibre, etc. Not only can you record exactly what you eat in the day, you can also enter your own custom foods if they're not already in the database. I find it useful for deciding between two meals when you don't know what would be better for you. For instance if I can't decide between a falafel and vegetarian hand-rolls I'll type both into the food searcher and then see which one is better for my calorie and fat intake for the day.
There's also a help menu at the top of the page. This has a link titled 'Getting Started'. It could be worth checking it out.