1) Read the first couple chapters of Introduction to Algorithms (Cormen et. all) enough times to know it cold. Something in there will come up. 2) Dedicate a day or so to browsing pertinent Wikipedia articles. Simply read as much as you can.
The former gives you some depth. The latter, breadth. Outside of off-the-wall Wikipedia articles, you should not be discovering anything radically new. If all goes to plan, you should be able to answer the bulk of the straight engineering questions. If you're lucky, one of them will click with a Wikipedia article you've just read. See: Fragmentation, Skip Lists, Virtual Functions, whatever. Read lots. Even if emulated, breadth counts.
If you get lost on step 1, this isn't the job for you (right now).
Good luck!
Learn Big-O notation for various algorithms
One thing that was recommended to me and I didn't do was the Topcoder practice rooms. In retrospect I think that could have been useful.
http://www.amazon.com/Cracking-Coding-Interview-Fourth-Progr...
Learn your algorithms.
Learn "O()" notations.
As well as the above they seem to look for a good GPA, good school, and a record of having achieved things.