I don't like English dictionaries that use pseudo-IPA to indicate pronunciation. I've seen none indicating that most plosives should be aspirated, but when they're in "sp", "st" and other combinations they're not - that I had to discover thru reading linguistics books.
And no dictionary I've seen yet mentions the English sandhi rules, which once you discover (even if for yourself) your pronunciation suddenly sounds much better to your native speaker friends, even if they can't state why.
I've had to discover for myself that "of" is always pronounced as "ov" when next word starts with a vowel, that the "-s" ending (of plurals and possessives) is usually turned to "-z" when surrounded by dentals of followed by a vowel, and some other rules.
Is there a book or dictionary that lists all these? This would be an enormous aid to those of us who study English as a Second Language without the aid of naive speakers - who, anyway, most of the times are not aware of these rules even though do recognize a good pronunciation when you use them.