I think it's hard to beat the CLRS book (Introduction to Algorithms by Cormen, Leiserson, Rivest, Stein) in terms of depth, breadth, or clarity of explanation. Algorithm Design, by Kleinberg and Tardos, is also very good and not nearly as intimidating.
Personally, even as someone who enjoys learning out of books most, starting from scratch with an algorithms textbook seems like a rough introduction to the subject. I think it would be easier if you watched video lectures, as there are some very high-quality lectures available on the internet nowadays. In general I'd encourage you to search MIT opencourseware and other similar offerings. This class might be a good option that I've used to brush up on some basic stuff earlier this year (scroll down to "Videos"). Unfortunately the videos there are considerably low-quality; you may be better off finding another class. Youtube EDU also has some filmed lectures that may be useful, particularly if there are some specific topics you're interested in.