A fast and easy way to get familiar with this if you aren't (and don't want to watch the OCW lectures that cover it):
Look up all the common data structures -- arrays, linked lists, hash tables, vectors, heaps, trees of various sorts, etc -- and chart out the big-oh for the operations they support. You should probably also be familiar with amortized analysis, which is what people mean when they say that hashtables or vectors have O(1) insert.
The Javadoc for java.util has interesting details on concrete implementations of these concepts; see TreeMap for example.
Look up all the common data structures -- arrays, linked lists, hash tables, vectors, heaps, trees of various sorts, etc -- and chart out the big-oh for the operations they support. You should probably also be familiar with amortized analysis, which is what people mean when they say that hashtables or vectors have O(1) insert.
The Javadoc for java.util has interesting details on concrete implementations of these concepts; see TreeMap for example.