To view all the series and cards in your collection, go to your profile (also your home page within NeonMob), and select the "View a Series..." dropdown list. This menu displays all series you have ever collected. Select any these series and you will see the cards you own along with ways to trade for the cards you need.
Another quick link to your collection is the "Your Most Recent" section of your profile. Click "Your Series" under any of the series you recently collected to be brought to your cards.