Although I liked Effective Java a lot, and it does contain a lot of advice relevant to many OO languages - it is the opposite of language agnostic: It's very Java-specific. Much of the content is irrelevant except in Java itself; and some of it is the opposite of "Effective language X". For example, it has a section named "Prefer lists to Arrays"; any C++ programmer will tell you the opposite (and that goes down to some of the arguments, such as Java not supporting generic arrays while C++ supports them).

So - good book, but not for this purpose.