Hi, and welcome! If you want to try and find BookCrossing books, see the "go hunting" pages under the "books and people" tab; that will show you locations where books have been released within the last 30 days. If you click down to specific locations, you can see lists of books; clicking on the books will show you the individual release notes, which *may* include detailed descriptions of where the books were left, and possibly even photographs.
That said, there's no guarantee that the books will still be at the same spot - and not everyone likes to make specific release notes, so you may see lots of entries that only say "somewhere in town" or something similarly vague. So it's a bit of a gamble!
And do check out the site FAQ and "How to BookCross" entries under the "information" tab; that's a good way to learn about BookCrossing.