To set the reading challenges you're likely seeing post to your dashboard from your followed booklikers, it's at http://booklikes.com/goodies/readingchallenge .  If you lose this post/link, it's under "goodies" on the main menu (so is the Reading Challenge widget code for your blog, direct link http://booklikes.com/goodies/widget ).

Click the "read more" if you're in dashboard view and you'd like creenshots (you'll still stay on booklikes without being redirected to another website/blog):

The reading list feature fo booklikes is at http://booklikes.com/apps/reading-lists or you get to it by selecting "apps" from the main menu.   Screenshot:

If you tell booklikes to add all books from the reading list, it creates a shelf named the same and adds them.   Unlike listopias on goodreads, the lists don't show on the book pages and the list creators manage (you can comment to request updates or discuss something).  No voting campaigns or paid promoters gaming the lists, yay!  Example screenshot from reading list Read Alike List for "How It Went Down" 2015 Coretta Scott King Author Honor Book :

How do I tell from the book page, when editing my shelves or search results that I've already shelved a different edition of the book?

UPDATED WITH AN ANSWER:  ( thanks to Tannat's comment) On search results you'll see a vertical green bar if you've shelved an edition.  (Still not sure about on book page).  Screenshot showing bar:

For example, when I am updating my shelves, someone's post has me click open a book page or maybe do a search on ISBN of book in hand.

(When my edition has been correctly combined, of course.  I realize if there are stray editions that I first need to click "report" and ask a librarian to combine with correct work.  And that there's a known bug where the narrator name as author causes audiobooks to not combine with their print/ebook editions -- again that should be reported to get combined and edition edited so narrator says narrator instead of author.)

It's getting close to the end of the year but there's still time to challenge yourself to read a few more books before 2014 gets here.  If you've imported your bookshelves from somewhere else you may have already completed a challenge and you can use books already shelved (as long as the  'Date Read' column has been filled in with a date this year) for this.  Any books added to the shelf at a later date are automatically added to your widget for you (just remember to compete the 'date read' bit.)

Lets add a Booklikes Challenge Widget to our sidebar to show everyone what massive bookworms we are :)

Taking a break from sorting out my shelf categories and I thought I'd do a tiny tutorial on changing the background colour of the comments section below posts.  I use template one (the default choice) and this method may or may not work for the other styles.