I recommend to prep Financial Modelling and Power Point.
1) Financial modeling - the best course I know is Training The Street. Take Financial Modeling, Valuation, Maybe LBO
2) Power Point - Google for MBB presentations and try to replicate them. Search for tips and tricks in books / internet in parallel. Plus read "Say it with charts" and "Pyramid Principle"
And finally - take a long vacation before starting your job;)