Here is an inheritence graph of some of the more important Java collection classes of Java 1.5. Instantiateable classes are blue and rectangular, abstract classes are just rectangular, and interfaces are elliptic:

Java Collections Hierarchy Small

As a sidenote, have written this post almost a year ago and just found it in my drafts. I have completely forgotten about it! So here it is anyways. And now I remember why I did not post it: becauseit contains only a minor subset of the collections! Thanks Artur Biesiadowski for reminding me about that…