Amidst all the dissatisfaction with BookLikes recent lack of communication with its members, I've heard people mention they are still having problems finding books in the database when they search, so here are two things people might find useful:
Thing 1: If you have access to the book's ISBN (or ASIN), use that in the search box. That will find your book. If it's not in the database (say it's a brand-spanking new release), BookLikes will actually go out and fetch the record from whatever data feed is handy (I assume it's Amazon's).
Edit: Chatting with Tennat below, I recall a few ebooks that didn't come up when I searched by ISBN, so let me revise my over-confidence above and say searching by ISBN will get you your book... 8 out of 10 times? Hopefully that's closer to accurate. I add a lot of editions as a librarian here, and I've only had to add manually a couple of times.
Thing 2: You can use URLs from publishers' and book sites in the BL's search box. I discovered this by accident when I wanted to pull an ISBN out of the URL; I pasted the whole URL into the search box, but before I could edit it down to just the ISBN, BL had already found the book. I've since done this with URLs from several sites and they've all worked to find the book.
Searching by title should be getting easier, but if different editions haven't been combined properly, you may not find what you're looking for: the BL database only indexes the main edition of any book. If you're struggling to get a book to show up and you don't have access to an ISBN (or ASIN), start a thread about it in the Official BookLikes group, or let a librarian know and it'll get fixed.