I feel that the LaTeX syntax is quite easy to use. However, I'm starting to include diagrams in my document. I've discovered the exciting world of MetaPost! The thing is, the MetaPost syntax looks a little more intense than LaTeX... So I figured I'd buy a book on it. I'm wondering though, whether it's better to buy a generalised book that talks about both LaTeX (maybe I can learn something) and MetaPost, or should I buy a book that specialises on only MetaPost? Given that the specialised book is going to be more involved, I'm thinking something introductory might be better.
If it's relevant, the document is a software project specification; so it contains UML and data flow diagrams. To be honest, I'm actually wondering if LaTeX is relevant to this question -- if this is the case, is there a definitive book for MetaPost?
Udpdate:
I just realised that I was unwittingly using MetaUML, not raw MetaPost. So for those that don't know, MetaUML is a package for MetaPost. As user Little Bobby Tables has pointed out, there is no book for MetaUML.