If you see an item that you like, and want to save it to quickly get back to later - simply click on the heart icon located below the item's image. This can be done from the item page or the sale page. The heart will now be red as a confirmation of following. Any items that you have already bid on will automatically be in your "Following" list.
To view all of the items that you have been following or bidding on so far, simply visit your "Follow" list. You can unfollow items by clicking the heart again.