Ah, quite simple if not very intuitive.
If you go to any manga page or the page for a series, you will have a menu to the left of your name. Just click on that and choose the appropriate entry. You'll have to add stuff to Read manually, though. If you see what you have in your lists, just hit the Lists option on the top bar. You can add other lists which will appear in the other menu there.
Hopefully that helps.
