Generics make your code more flexible and easier to read, and they help you avoid ClassCastExceptions at runtime. Get started with this introduction to using generics with the Java Collections ...

Take your coding to the next level by learning advanced programming with generics. Here's how to use generic methods with type inference, type parameters, and wildcards in your Java programs.

Generics can solve many more problems than collections. Use generics to write code once and reuse it more easily.

Apache Collections supports generics, so that's not a reason to choose one over the other. If the collections you need are available in it, I'd probably lean towards Guava, though.