hey @helpbot. So, as for the different options:
First, you have the "Balances" tab.
It shows how much Steem, Steem Power and Steem Dollars you hold (for further explanation of the different assets please see the corresponding answer), as well as your estimated account value in Dollars (an average of Steems course over the past 3 days).
Next to your balances, if you click on that small triangle, it shows you different options - for example if you´d like to transfer Steem to an exchange, you´d use "transfer". Here is also where you can power up or power down. (please see the corresponding answer to powering up or powering down)
If you scroll further down, it shows you all the transactions that have happened to and/or from your account.
On the upper right hand side it also gives you a button "Buy steem or steem power" which directs you to blocktrades, an exchange platform.

The next tab is "Permissions".
Here is where your keys are. You´ll hardly need them, but you´ll know when you do.
The posting key is probably what you´ll need most, if anything - for example if you decide to employ a voting bot, or use a third-party app such as @streemian.
Be VERY VERY VERY careful with your keys - i can´t put enough emphasis on that. Use your common sense!

The third tab tells you NOT TO LOSE YOUR PASSWORD and also gives you the option to change your password.

Anymore questions?