Pending tasks can be easily found on four levels:
From the top right-hand side of your screen, you can see at the bottom of the opened window, your pending and past due tasks.
If you have an agency account, you'll be able to see a breakdown of the new and past due tasks in the top left drop down menu:
In your Tasks tab, you can see the breakdown of new and past due tasks for each active module:
From your Tasks tab, you can expand a module. Blue and red dots to the left of the individual tasks indicate new and past due.