An ArrayList is the successor to the Vector (both are, in effect, resizeable arrays).
A linked-list is something different.
Read the JavaDocs for a description.
http://java.sun.com/j2se/1.4.2/docs/api/java/util/LinkedList.html Better yet, get a book or tutorial on data structures. This one is common to most languages.
The HashMap is the successor to HashTable.
All of the Collections are contained in the java.util package:
http://java.sun.com/j2se/1.4.2/docs/api/java/util/package-frame.html The second volume of "Core Java" devotes a whole chapter to them.