Attending a seminar/workshop gives you the opportunity to ask follow up questions and often the information when presented in seminar format is clearer and more accessible if that makes sense. So even though you've read books, there may be a little nuance that you haven't picked up on from the books that they can help you discern. Also, books are very broad brush and cannot possibly account for all the different experiences people are having in their individual circumstances. With a seminar, you have the opportunity to say hey that's great and it almost sounds like our situation but we're slightly different in this way - how does that change, if at all, what we should be doing? For instance, not all methods are appropriate for all ages of baby/toddler. So while the strict cry it out method may be appropriate for a 4-6 month old, it may not be for a 14 month old. I would go and as one of the other posters mentioned, hopefully you meet some other folks and make some new friends.
Good luck!