I've just returned from the US after some hour building.
I ended up ordering from a US pilot store online and paid only a few dollars for the items. Can't remember which one now though - google may be a good bet.
However, to get a feel for things, I suggest you take a look at
www.skyvector.com - whilst all the usual warnings about chart currency etc. apply, this will at least give you a good feel for how the US charts differ and what you might/might not be able to do when over there.
Also, another book that I found really useful over there is called "Say Again Please" - it describes how the US airspace/ATC system works and is good reading for us who are used to different ways of working this side of the pond.