1) get a good c/c++ book. a good one that's downloadable courtesy of the author bruce eckel is
here
2) get a good book on windows programming. a fairly good book on windows/windows ce/pocket pc is doug boling's "programming microsoft windows ce"...i believe the 3rd edition is just about to come out...2nd ed. book info
here
3) become one with the "mobile and embedded development" section of the msdn site at
http://msdn.microsoft.com/. some decent tech articles/examples as well as latest info and sdk info.
4) google search...you'll find numerous sites such as
http://www.pocketpcdn.com/